How odd is that? Since the problem is not firefox-centric... since Safari and Chrome are also effected... I find it hard to believe it was the Firefox update that did you in... UNLESS that update was a subsystem, and *not* Firefox itself. I would look for subsystems that effect all three, and not IE. The likely culprit would be Adobe Flash, with Java being a close second.
Try uninstalling Flash, using their universal uninstaller. This will fully uninstall BOTH the ActiveX (IE), and standalone (everything else) versions of Flash completely. RESTART. When done, Check for JOY. IF JOY, then you will have to re-install Flash in both IE and in Firefox (which will install also for Safari and Chrome) to get right.
If no JOY, next go to Add&Remove Programs, and uninstall ALL versions of Sun Java... and while you are there, any toolbars, especially oddball ones... RESTART. Check for JOY. IF JOY, reinstall the newest Java. Check for JOY. IF JOY, AND IF YOU REALLY MUST, reinstall toolbars one at a time, checking for JOY each time. If any one tool bar causes grief, uninstall it and leave it gone.
Look at RealPlayer, and any other subsystem (MediaPlayer add-ons, etc)that might effect all non-IE browsers, using the same uninstall, look for Joy, reinstall method.
If none of the above, I would sincerely be looking for a virus problem, or adware... Normally I would have this step first, but most bugs will crap out IE before any of the Mozilla based stuff.
I know that Flash has messed me up when installing new FireFox versions in the past. Your post takes this a step further.