I don't know if you have got an answer on this. I have just registered seconds ago for this topic. This is the exact problem that I have on my machine, Asus A8N SLI-Premium, X2 4200+ Dual Core, Nforce 4 SLI chipset. Geforce 7600GR graphics, Quickcam 5000 Pro. XP Pro SP-2 fully updated on WIndows Update.
The solution for me? Uninstall Quickcam software BUT NOT uninstall the drivers (I got these 2 items on the Add and remove programs menu). After this my Start Menu returned to normality. I was using 9.5.0 Logitech SW.
I could not detect this problem before, after making a registry clean with JV16 Power Tools 2006 I started to have the issue, and removing the Logitech SW was the only solution.
Logitech Microphone also conflicts with the hardware acceleration of my SB Audigy 2 card. I have to disable it if not in use.
I thing I will try to reinstall WIndows on this machine and see if the the Logitech software works again.
Hope this helps.
