Min Kwan Park's blog was making the rounds of the various Microsoft blogs yesterday, but I thought I'd also post a link for anyone who missed it (and also so I can find it again easily in the future). He's posted a helpful checklist of things to try if you can't make the VS.Net debugger work properly. You can find the entry here: http://blogs.msdn.com/mkpark/articles/86872.aspx. He also plans to keep updating the post as more issues arise, so its a good article to check back on periodically.