Hi,
That's because the zip includes a mail.sql with non translated strings:
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (1, 'en_US', '{WEB_TITLE} - Someone has a question about your listing', '<p>Hi {CONTACT_NAME}!</p><p>{USER_NAME} ({USER_EMAIL}, {USER_PHONE}) left you a message about your listing <a href="{ITEM_URL}">{ITEM_TITLE}</a>:</p><p>{COMMENT}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (2, 'en_US', 'Please validate your {WEB_TITLE} account', '<p>Hi {USER_NAME},</p><p>Please validate your registration by clicking on the following link: {VALIDATION_LINK}</p><p>Thank you!</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (3, 'en_US', '{WEB_TITLE} - Registration successful!', '<p>Hi {USER_NAME},</p><p>You\'ve successfully registered for {WEB_LINK}.</p><p>Thank you!</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (4, 'en_US', 'Look at what I discovered on {WEB_TITLE}', '<p>Hi {FRIEND_NAME},</p><p>Your friend {USER_NAME} wants to share this listing with you <a href="{ITEM_URL}">{ITEM_TITLE}</a>.</p><p>Message:</p><p>{COMMENT}</p><p>Regards,</p><p>{WEB_TITLE}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (5, 'en_US', '{WEB_TITLE} - New listings in the last hour', '<p>Hi {USER_NAME},</p><p>New listings have been published in the last hour. Take a look at them:</p><p>{ADS}</p><p>-------------</p><p>To unsubscribe from this alert, click on: {UNSUB_LINK}</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (6, 'en_US', '{WEB_TITLE} - New listings in the last day', '<p>Hi {USER_NAME},</p><p>New listings have been published in the last day. Take a look at them:</p><p>{ADS}</p><p>-------------</p><p>To unsubscribe from this alert, click on: {UNSUB_LINK}</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (7, 'en_US', '{WEB_TITLE} - New listings in the last week', '<p>Hi {USER_NAME},</p><p>New listings have been published in the last week. Take a look at them:</p><p>{ADS}</p><p>-------------</p><p>To unsubscribe from this alert, click on: {UNSUB_LINK}</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (8, 'en_US', '{WEB_TITLE} - New listings', '<p>Hi {USER_NAME},</p><p>A new listing has been published, check it out!</p><p>{ADS}</p><p>-------------</p><p>To unsubscribe from this alert, click on: {UNSUB_LINK}</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (9, 'en_US', '{WEB_TITLE} - New comment', '<p>Someone commented on the listing <a href="{ITEM_URL}">{ITEM_TITLE}</a>.</p><p>Commenter: {COMMENT_AUTHOR}<br />Commenter\'s email: {COMMENT_EMAIL}<br />Title: {COMMENT_TITLE}<br />Comment: {COMMENT_TEXT}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (10, 'en_US', '{WEB_TITLE} - Edit options for the listing {ITEM_TITLE}', '<p>Hi {USER_NAME},</p><p>You\'re not registered at {WEB_LINK}, but you can still edit or delete the listing <a href="{ITEM_URL}">{ITEM_TITLE}</a> for a short period of time.</p><p>You can edit your listing by following this link: {EDIT_LINK}</p><p>You can delete your listing by following this link: {DELETE_LINK}</p><p>If you register as a user, you will have full access to editing options.</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (11, 'en_US', '{WEB_TITLE} - Validate your listing', '<p>Hi {USER_NAME},</p><p>You\'re receiving this e-mail because a listing has been published at {WEB_LINK}. Please validate this listing by clicking on the following link: {VALIDATION_LINK}. If you didn\'t publish this listing, please ignore this email.</p><p>Listing details:</p><p>Contact name: {USER_NAME}<br />Contact e-mail: {USER_EMAIL}</p><p>{ITEM_DESCRIPTION}</p><p>Url: {ITEM_URL}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (12, 'en_US', '{WEB_TITLE} - A new listing has been published', '<p>Dear {WEB_TITLE} admin,</p><p>You\'re receiving this email because a listing has been published at {WEB_LINK}.</p><p>Listing details:</p><p>Contact name: {USER_NAME}<br />Contact email: {USER_EMAIL}</p><p>{ITEM_DESCRIPTION}</p><p>Url: {ITEM_URL}</p><p>You can edit this listing by clicking on the following link: {EDIT_LINK}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (13, 'en_US', '{WEB_TITLE} - Recover your password', '<p>Hi {USER_NAME},</p><p>We\'ve sent you this e-mail because you\'ve requested a password reminder. Follow this link to recover it: {PASSWORD_LINK}</p><p>The link will be deactivated in 24 hours.</p><p>If you didn\'t request a password reminder, please ignore this message. This request was made from IP {IP_ADDRESS} on {DATE_TIME}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (14, 'en_US', '{WEB_TITLE} - You requested an email change', '<p>Hi {USER_NAME}</p><p>You\'re receiving this e-mail because you requested an e-mail change. Please confirm this new e-mail address by clicking on the following validation link: {VALIDATION_LINK}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (15, 'en_US', '{WEB_TITLE} - Please validate your alert', '<p>Hi {USER_NAME},</p><p>Please validate your alert registration by clicking on the following link: {VALIDATION_LINK}</p><p>Thank you!</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (16, 'en_US', '{WEB_TITLE} - Your comment has been approved', '<p>Hi {COMMENT_AUTHOR},</p><p>Your comment on <a href="{ITEM_URL}">{ITEM_TITLE}</a> has been approved.</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (17, 'en_US', '{WEB_TITLE} - Validate your listing', '<p>Hi {USER_NAME},</p><p>You\'re receiving this e-mail because you\’ve published a listing at {WEB_LINK}. Please validate this listing by clicking on the following link: {VALIDATION_LINK}. If you didn\'t publish this listing, please ignore this e-mail.</p><p>Listing details:</p><p>Contact name: {USER_NAME}<br />Contact e-mail: {USER_EMAIL}</p><p>{ITEM_DESCRIPTION}</p><p>Url: {ITEM_URL}</p><p>Even if you\'re not registered at {WEB_LINK}, you can still edit or delete your listing:</p><p>You can edit your listing by following this link: {EDIT_LINK}</p><p>You can delete your listing by following this link: {DELETE_LINK}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (18, 'en_US', '{WEB_TITLE} - A new user has registered', '<p>Dear {WEB_TITLE} admin,</p><p>You\'re receiving this email because a new user has been created at {WEB_LINK}.</p><p>User details:</p><p>Name: {USER_NAME}<br />E-mail: {USER_EMAIL}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (19, 'en_US', '{WEB_TITLE} - Someone has a question for you', '<p>Hi {CONTACT_NAME}!</p><p>{USER_NAME} ({USER_EMAIL}, {USER_PHONE}) left you a message:</p><p>{COMMENT}</p><p>Regards,</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (20, 'en_US', '{WEB_TITLE} - Someone has commented on your listing', '<p>There\'s a new comment on the listing: <a href="{ITEM_URL}">{ITEM_TITLE}</a>.</p><p>Author: {COMMENT_AUTHOR}<br />Author\'s email: {COMMENT_EMAIL}<br />Title: {COMMENT_TITLE}<br />Comment: {COMMENT_TEXT}</p><p>{WEB_LINK}</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (21, 'en_US', '{WEB_TITLE} - Success creating admin account!', '<p>Hi {ADMIN_NAME},</p><p>The admin of {WEB_LINK} has created an account for you,</p><ul><li>Username: {USERNAME}</li><li>Password: {PASSWORD}</li></ul><p>You can access the admin panel here {WEB_ADMIN_LINK}.</p><p>Thank you!</p><p>Regards,</p>');
INSERT INTO /*TABLE_PREFIX*/t_pages_description (fk_i_pages_id, fk_c_locale_code, s_title, s_text) VALUES (22, 'en_US', '{WEB_TITLE} - Your ad is about to expire', '<p>Hi {USER_NAME},</p><p>Your listing <a href="{ITEM_URL}">{ITEM_TITLE}</a> is about to expire at {WEB_LINK}.');
'en_US'. Given the fact that those fields already exist on the database, hence that error, but anyway the rest is installed fine, so the language is almost fully operative (no mails templates in Hindi though).
Regards