WPF apps won't run from within VS2005

Hi,

I am have been running into an issue lately where my WPF applications exit
prematurely with only the following message:

"The program '[5040] applicationname.vshost.exe: Managed' has exited with
code -2146233082 (0x80131506)."

While I can sometimes run a program I can also get the above message for no
apparent reason. Does anyone have any ideas?

I should point out that if I run the same application from something like
Expression Interactive Designer, I never get the same problem.

Cheers,
Clint