Along with IIS Reset, Are you debugging is the most commonly heard phrase in the Technical room. With shared projects, the problem is someone could be debugging whilst someone maybe working on other parts of the app. Due to performance, debugging creates an almost unusable project for all other users.

Maybe the hotfix that Scott Guthrie blogs about in the below post is the fix for this frustrating problem? 

http://weblogs.asp.net/scottgu/archive/2007/08/21/public-hotfix-patch-available-for-vs-2005-f5-debugging-performance-issue-with-asp-net.aspx