I fully agree.
If you install ATI display drivers, then uninstall them and stick in an Nvidia board instead and reboot, you'll still have two ATI entries showing up in the task manager. I'm like, wth? How damn difficult can it be for a multi-billion corporation to write an uninstall script that removes all the crap it put there in the first place? It's unforgivably sloppy.
I had a similar problem where going from a 4870 to a 5870 cause the 4870 driver to auto install after removing the cat driver for the 4870. I had to remove the 4870 driver (not the cat driver but the drive that auto loads when you uninstall CCC) do to oddities in a particular game using a 5870. It make me wonder if I have to deactivate pagefile, indexing, etc in those examples. Which brought me to this question: When you disable pagefile is it really disabled in Win7 (IE: pagefile.sys removed from the hard drive)? I get the impression that it's not fully removed although I've not fully tested it.