Also random crashes appear.
And this i not happening with server 2008 (not r2) on same machine.
Had 2008 running without problem until I desided to give R2 a go.
.net 3.51 did the trick.
.net 4 is NOT enough.
Crashes also stopped when copying.
Thank you thank you thank you!
I remember now that I figured this out before... and then I forgot - don't you hate that?
I found these other threads - will update them with this information.
Confirming that this still solution still holds vaild. Demoxx, thanks for sharing!