Orcas Bug? Test View

I have find the quickest way of writing code these days, is to sort of follow Test Driven Development.

I am not anal about it, I just believe it is quicker for me to write code against a unit test, and debug the unit test, rather than the application. This strategy has saved me a ton of time.

Now that I am using Orcas in my commercial environment, annoyingly enough I am getting the following error when i attempt to debug a unit test:

"Failed to queue test run 'ch3@20070806PC01 2007-09-03 13:00:53': Unable to start program 'c:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\vstesthost.exe'."

If i just run the test, it works fine, it is only when i attempt to debug it.

UPDATE
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I've discovered what was causing the problem, I have a little batch file, which i haven't update which starts the WebDevServer (Cassini), but this is launched from .NET Framework 2.0.

I never run VS directly (in my work environment), I always attach to the debugger.
For somereason when i debug the unit test, it seems to clash with the WebDevServer, and it dies a horrible death.