FF Content tab is blank

Windows 7 desktop clients. IE 8.07601.17514. FF 7.0.1. Percussion CMS Version 6.7.0 Build 200906P01.

We can see the content tab list in IE but we get a blank content list area in Firefox (everything below the tab header is blank). This is affecting all Windows 7 users. We all saw the content list the first time we viewed it in Firefox, but after changing tabs and returning to the Content tab, none of us have seen it reappear. It doesn’t matter if the java temp files are all cleared. The behavior remains the same.

Our developers require Firefox because IE has not allowed them to embed javascript into content posts for several years. They rely on Firefox to allow them to embed javascript in posts.

Any help or insight would be greatly appreciated.