I am a developer and also use Visual Studio 2010 and Avast. Since the update on March 9th, 2012 I have had problems.
I experience random IE 9 "Cannot display webpage" This is unrelated to Visual Studio. However, I can reproduce this error by simply setting a debug point in any of my web applications, run the application, hit the debug stop point, then tell the application to resume. In short, I cannot resume from a debugging session.
I know it is related to Avast as when I disable all the shields, I can debug normally. When I enable all the shields, I cannot resume from a debug session. When I tried disabling the shields one-at-a-time, I still got this error. Only when I completely disable all shields do I get normal behavior. Also this eliminates all other problems with IE 9 "Cannot display webpage."
I would at least have someone acknowledge this is problem.