I think I finally figured this out by Googling and searching through Bugzilla. It was driving me crazy. I would load a page and then it would go blank, or I would load a page in one tab, go to another, then come back to a blank page. It would come back when reloaded, but often woudn't stay loaded. Here's what I think is the fix: https://bugzilla.mozilla.org/show_bug.cgi?id=516698 Disable Flash Plugin Version 10.0 r32 I'm not having the problem any more.

<sigh> Yes I am still having it with the earlier version too. Is there a substitute for the Flash player?

Finally found another solution. Using current Flash Player 10 like before, which helps me see important things like Google Analytics, but disabled all RealPlayer extensions/addons to Firefox 3. So far this is working.