I have seen references that a version of MS .NET Framework (3.5?) was needed for ATI GPU. The newest version of .NET I have on my ATI box is 2, but I do have both 32 & 64 bit Microsoft Visual C++ 2008 Redistributable Package installed and my 4870 has been running fine with and without the app_info.

Dunno if that’s what the problem is on your end but installing the C++ libraries only takes a minute or two, worth a try if you already do not have them installed.
That was the ticket! 2 5830s, 1 4870, and 8 cores are now fully functional. Thx for your help guys.