Update....
Ive got some info from Microsoft regarding the Visual Studio crach which you experience when opening maps when you have test projects. The scenario is discussed on the following link:
http://geekswithblogs.net/michaelstephenson/archive/2006/10/18/94458.aspx
The response from Microsoft was basically as follows:
"The investigation done by the dev team has determined that the problem is caused in part by code calling Marshal.ReleaseComObject on a project of type Microsoft.visualStudio.TestTools.Tips.TuipPackage.TestProject.
The recommended course of action is to implement a workaround by separating any projects using Microsoft.visualStudio.TestTools.Tips.TuipPackage.TestProject from any BizTalk projects by using separate solutions - i.e. Create one solution that contain BizTalk projects, and then a separate solution that contain any TestProjects. This workaround should eliminate the memory corruption error.
The issue is solved on next version of Visual Studio, that is going to be released at the end of 2007. Visual Studio is aware of the issue and knows the impact of that on your site but a fix is not going to be released to solve this problem as the replication of the code to solve it, will be a significant change in the product."
So theres the work around, and also look forward to the fix soon :-)