Found the issue. The new version of openCL conflicted with the 4850 for some reason. And by the way, with both cards, I am running a significantly faster FPS. So the guy before me can keep his opinions to himself.
The steps I took to fix that were:
1. Check out files named amdocl64.dll, amdsc64.dll and OpenCL.dll (in C:\Windows\system32) and amdocl.dll, amdsc.dll and OpenCL.dll (in C:\Windows\SysWOW64). If they don’t have the same date, they are likely the cause of the problem: it seems that the AMD APP SDK Runtime installer/uninstaller has trouble updating/removing them, so you end up with some from a version and some from another version, which just isn’t able to work.
2. Uninstall the AMD APP SDK Runtime, for me I ran setup.exe in
3. delete any of the remaining files spotted in 1. that may be left in system32 and SysWOW64
4. reinstall the AMD APP SDK Runtime. I installed an older version.
AMD-APP-SDK-v2.5-Windows-641 (v2.8 had the same issues)
5. reboot, I didn't need to but it might help.