Ok. I'm moving this to a thread so your questions aren't spread through a bunch of places...
If it's running on DNETC and completing things successfully, that answers a lot of the questions. We know it works...
On PG - make sure you have the OpenCL support installed and .NET 3.5 installed. And wait for this batch of bad WUs to be done with. Then try it again.
As far as Collatz, I'm not sure what the problem is. Just about every ATI card should work there...