There seems to be a problem with SS2 and the latest Microsoft XP/2000 hotfixes
If you updated for these in the last couple of weeks then uninstall them. Seems to be some debate as to whether its 840987 or 841533 that affects it - some say one some say the other.
Whichever, it completely knackered me as it trashed my SS2 and knocked out my library which I was part way through putting on and hadn't yet backed up
Reinstalling SS2 is a real pita as it seems you must delete all previous trace of it
See click here