Mark, Regardless of how you set up the camera the buffer will not get to 100 frames as buffer capacity as shown in r=. Nikon confuses buffer capacity with max burst 'capacity'. With my D300 I am able to get better than 90 continous shots in one straight burst using size priority and fine medium without an MB-D10 attached. In your shooting menu what is d6 set for? It is factory set for 100 by default, has it been changed? It is also possible that you have a problem card, or cards, since you've reported both Kingston and Sandisk - but this is unlikely. I'd suggest setting up CL on 6 or7 fps and check again, using the precautions listed by the other posters and if you can't get higher than twenty something frames then you'll need to explore getting the camera serviced.