Just got it working! So relieved..

My 6970 is mining at an average 386mh/s using 2 cores of my CPU and with the flags -v -w 128 on GUIminer, it also works on BFGminer and cgminer.

Solving the problem was greatly assisted by going into safemode a number of times and using 'driver fusion' the poster above me recommended (Thanks!) to remove all traces of nvidia and ati drivers (besides the registry entries because it doesn't do that unless you purchase the program, which worried me at first).

Apparently the issue was caused by not having VERY SPECIFIC DRIVERS and complicated additionally by not having full un-installations of the earlier drivers I installed, that being said - The LATEST drivers that were RECOMMENDED to me by ATI were the drivers that caused this issue to begin with.
I tried downloading different versions of the 'ATI stream SDK' which is now known as the 'AMD app SDK', that didn't work oddly enough..

I personally needed http://support.amd.com/us/kbarticles/Pages/AMDCatalyst126beta.aspx  NOTHING else worked.

No idea why, all I know is that I went through an inordinate amount of trouble to get this working.
I would never wish this upon anybody... So I hope my posting this helps somebody that needs it..

Now all I need is a massive bong rip and a 6 pack to help me forget this hellish experience..

Thanks for that suggestion, I'll be trying it tomorrow and I'll update my post..
Nothing has worked so far.. That feel..
Beyond frustrating.

Lowering the intensity didn't do it unfortunately. Attempting to revert catalyst to 12.6, I'll update this post momentarily.

I'm having this exact problem, except I'm mining with a 6970 and an nvidia 660ti. The 660ti mines flawlessly, but I get the errors with the 'Cayman'/6970.

Sorry for the gravedig, but this is a last ditch effort..

It may be worth noting that the 6970 doesn't have a display connected to it, my 660ti does. Does anyone have any ideas on what is causing the problem?