I had noticed that my two cards were running underclocked (like 250MHz versus the advertised 825MHz) when I first got my machine last fall. I tried all kinds of things to fix it, and eventually ended up installing RivaTuner and using that to manually configure the cards to what they were supposed to be and that fixed everything. It sounds like these fixes will correct my problem too so that I no longer need a 3rd party app to manage the cards anymore.

Great find.