I now have the same problem, though, I've had my Zune working on that computer since I got my Zune in June. Nothing on the system changed between when it worked and didn't. I don't allow auto updates, and I haven't installed anything new in a few weeks.
I found something on MS site about repairing my DRM, but I don't want to do that just yet. The Zune software apparently does update if i leave the error message up, otherwise when I click ok, it closes. Anyone else have a suggestion?