Mining Alts with BFG lower then expected

Hey all I hope someone here can help me out a bit. I have been mining ALT coins for the last few months. However the only one I can get to work without shutting dos down right away is BFG miner. I run a 5970 which from what I am seeing should be hashing at about 700 Mhz however even after a bunch of tweaks I can only get it to run smooth on intensity 12 and it hashes at about 480-525 Mhz. Some times though when I first start it up it will hold 800 + for the first 5 minutes but after that is when I see it stay around these numbers and mine well for 24 hours. Any ideas on what I could code it to maybe help increase my hash rate? Also I am getting a few r290x's tomorrow and will be setting it up if you know of good settings for that one as well I would be greatful.

Thanks!