Under certain conditions opening Web projects from remote sites may become very slow. We've seen quite a few 'hang' reports submitted via 'Send Information to Microsoft' feedback (aka Dr. Watson). The reason is that sometimes XML editor (which is used when you edit web.config) may begin walking remote Web site file structure looking for XML schema files. Over a slower link this process may take minutes and IDE will appear unresponsive.
A hotfix is available at http://code.msdn.microsoft.com/KB958094
Program Manager | Data Programability