TinyMCE button UI weirdness

Anyone encountered this before:

I've tried using firebug to spot differences between this and a working version and I spot none.开发者_StackOverflow

A working version should like the following:

One of the CSS classes in your site is conflicting with the TinyMCE classes, and it is causing this problem. If you are using FireBug then look at the CSS break down on the right and side and see if there is any differences with any of the buttons and their parents.

Don't use FireBug but chrome or safari dom inspectors. Because firebug and TimyMce don't really work together.