Try to go in the preferences dialog
and click the "Reset dialog" button.
Make also sure to have updated your graphic card drivers
If you have still issues, be sure to post your full computer specs, OS and browsers used.
Please next time make sure to post a new thread (or at least post in a relevant thread, not just the first one that is up).
I hope this helps.Kyatric2013-01-07 06:28:30