Could be? Please give what version Osclass your using and any other info?
Are you able to change color schemes? Currently there are 4 choices.
What browser and what browser version are you using?
is it set to or not set to compatibility mode?
Have you tried in a different browser? I suggest Firefox.
Likely it is some sort of plugin conflict.
List what plugins you have installed.
Try disabling each plugin until the problem is resolved. Though unlikely, you may have to uninstall each plugin until issue is disappears. Though this can be time consuming if you have several plugins, it would go a long way in ruling in or out plugin conflicts.
Attached are screenshots of what you should be seeing.
I just tried it on IE, Firefox, Chrome and Safari and all worked well....
Tom