I've seen several folks having problems since we RTM'd VS2008. These usually manifest themselves as as things like "Download Manager - Error" when trying to access the bits (one example post).
Our release team and the MSDN team have been working to rectify these issues which have stemmed primarily from capacity problems on the edge network. Things should be working smoother now and updates to the Download Manager are also on their way as required to fix these problems.
I'm sorry if you have run into these problems. Obviously we'd like to see your experience be as smooth as possible. If you are still experience problems, please do let me know and we'll work to fix them ASAP. thanks!