Cannot open certain code behind files in Visual Studio 2008

Problem: When I try to open certain code behind files in Visual Studio the application hangs and maxes out one of my CPU cores.

Notes:

• There's really nothing unique about the code behind except for the fact that it is r开发者_StackOverflow中文版eferenced by two different ASPX pages. This, however, has never been a problem in the past.
• It's a C# code behind.
• I'm running SP1.

I finally figured out that this was related to a JS document outlining plugin that was installed and active.

This was difficult to trace as the problem was occurring for codebehinds and no other types of files. Moreover, it was only occurring for certain codebehind files.