Sounds exactly like what I reported earlier:
Looks like my rig with two 280X GPUs no longer works on this (its getting about 70 Kh/s). Would it be because the system doesn't have enough RAM?
I'm running a single 280X on my regular PC which has 6GB of RAM and that one's doing 1.8 Mh/s
Kinda makes it impossible to GPU mine it then with rigs set up to be able to mine scrypt coins. If other people are also getting this, I'd propose that we should step the nfactor back one level and keep it that way (would require a code change and advance notice though).
I don't think it'd fork the chain though since the rewards and target time would be identical, you'd just need to update to get the correct hashing power. Could anyone confirm this for me?