Recent crossfire issue - 3 GPU difficulty; but no issue with 2 GPUs

Hi all,


I run a 3 GPU crossfire setup with ASUS 5870s.

My other system specs are basically as follows:

Asus Rampage III Extreme
Intel i-7 950 CPU (but OC'd)
12GB OCZ Reaper 2000
OCZ PCI-e RevoDrive (120G)
WD Velociraptor 600GB
NB: The video cards are not OC'd


The difficulty:

I have been running the latest AMD drivers and Catalyst 11.8. However, without warning, in all full screen games (i.e. when crossfire is working), I am now getting a very significant 'rolling' of the screen, much like a vhold issue, or it could be perhaps described as severe horizontal flickering. It is extremely pronounced, and effectively makes games unplayable with 3 GPU crossfire enabled.

However, the issue does not exist with only 2 GPU crossfire (not at all).

I had thought this might be a hardware fault, but each of my three cards seem to be operating without issue (on their own).

I have tried downgrading Catalyst etc (just to version 11.6). I have otherwise attempted multiple driver wipes (the usual course of removing all installations, manually deleting any leftover files, cleaning out the registry and driver sweeper) and re-installations, but this has not helped the situation. I have also attempted adjusting the settings in Catalyst, but this has not proved productive either.


Accordingly, I am looking for any suggestions people may have - I am somewhat stumped, particularly as it seemed to start all of a sudden, when everything seemed fairly stable.


Thanks all for any assistance you may be able to offer, please let me know if you need any further details.

Regards,
Del52