Ok, here is the story
I thought it would be smart (yeah, right) to upgrade my DA, Webtop and WDK installation from 5.3SP5 to SP6.
So far so good.
The problem is that I have a 3rd party app that won't work anymore
Still being smart (!http://community.emc.com/images/emoticons/laugh.gif! ), I thought, whatever, I uninstalled everything, rebooted and then I reinstalled 5.3 SP5
DA: No problems
Webtop: No problems
WDK: Ouch. it says that it is already installed (Sp6) so I can't install it. The thing is that in the Add/Remove programs in Windowz (yeah, I know....), it doesn't show anymore. 
Of course, I thought I'd be smarter than Windowz and installed the Windowz installer tool I got from the MSDN that I already used for some other similar problems. Guess what, still no WDK in the list so I can't clean it up. 
Any suggestions (short from reinstalling windowz all together) ?
TIA