I have installed a beta of SP1 for Vista and have noticed it seems to kill the DesktopX 3.5 beta. Not too surprised by this given that they're both in beta. Just wanted to let folks know this to help them decide if they want to install the SP1 beta if it's available to them.
If you're results have been different from mine, LMK if there was some workaround you did to make it work.