I recently encountered a troubling problem while creating a BizTalk 2006 R2 solution. Everything was working fine until I tried to open the Orchestration Designer to edit one of the orchestrations I had been working of for a couple of days. Visual Studio crashed immediately. I tried a few things, but I could not open any orchestration without Visual Studio crashing (no errors in event log, no dialog, nothing...).
I finally fixed it by backing up and deleting my Visual Studio profile. The profile information is stored in a folder. This folder is located in C:\Documents and Settings\user\Application Data\Microsoft\VisualStudio\8.0.
I don't know what got messed up in the profile. Clearly some sort of VS/BizTalk bug.