Yes, the case was right next to a heat vent?!? I've moved it now. But, I don't know anything about how to tweak the configuration. Is there anywhere I can go to find out more? Any help would be great. Thanks!
Check here:
https://litecoin.info/Mining_hardware_comparison/raw_dataSee what mimicking some of those configs gives you (obviously use those that fit your card, which you never told us btw, only that it's from the 4800 series).