Got it to work.

1. Checked 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
C:\AMD\Support\13-1-legacy_vista_win7_win8_64_dd_ccc

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.

I am running an ATI 6670 and an ATI 4850.  Both are running with a monitor attached to each.  However, unless one of the cards is disabled in device manager in the control panel, none of the bitcoin miners will open.  They just crash.  Again, it instantly works when one card is disabled.

"xxxx.exe has stopped working".

It's the same for ALL of the miners (CGminer, GUIMiner, BitMinter, poclbm).  Bitminter doesn't start and produces an error log. 

Highlights:
# Problematic frame:
# C  [amdocl.dll+0x57bee]
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of Windows

I am running an ATI 6670 and an ATI 4850.  Both are running with a monitor attached to each.  However, unless one of the cards is disabled in device manager in the control panel, none of the bitcoin miners will open.  They just crash.

"xxxx.exe has stopped working".

It's the same for ALL of the miners (CGminer, GUIMiner, BitMinter, poclbm)

Reclarification post:

I have a ATI Radeon 4850 and 6670. Both are recognized in the catalyst control center, although it says "Disabled Adapter" for the card I do not boot into windows with the monitor attached to it (ie. Depending on which card the monitor is plugged into when I boot, it will run that card). Device manager shows both cards plugged in, and operating correctly with the drivers. I have tried booting with one monitor on each card to no avail.

I have read that you can run two seperate monitors from two different cards, but it is not allowing me to do this. Again, both cards work if the monitor is attached to one or the other card.

I am trying to fix this issue so I can solve my main problem which is I cannot get the secondary card (whichever it may be) to mine bitcoins unless the other one is disabled in device manager (only one card works at a time, if both are enabled, there seems to be conflicts).

Bumpity Bump

I can mine 100MH/s on my 4850, so I would prefer to keep it connected.

I am running an ATI HD 4850 and an ATI HD 6670 GPU in my computer.  Both power up and the drivers are installed (I can display desktop on either card).  However, unless I disable one of them in device manager, no Mining program will run. 

CGminer, GUIMiner and poclbm will crash on startup; and bitminter will not start either and produce an error log. 

PLEASE HELP!