Sorry for double posting here, the other post was misplaced and I think you should know about this bug.
WindowFX's feature Task Switcher causes a Division by zero error when you try to access it through its combination keys if you dont have any applications minimized or shown on screen.
I have reproduced this bug several times. I rebooted my machine and changed the combination keys but the problem persists.
You may reproduce it pressing the combination twice.
Application: Windows Explorer
Module: wfx.dll
Address: 0x000000006900d0d0
System: Windows XP SP2, AMD Athlon x64, 2Gb RAM, NVidia GeForce4 MX 4000, ForceWare 81.98, WindowFX 2.89[b].003
Application crash dump available on request.