Stumped by slow frame rate in CL and CH Modes - D300

I am hoping and expecting that I have forgotten some simple menu setting or better yet, this is one of those ID10t errors. But, here goes...

I haven't used the D300 in a while, so I took it out to the ballgame tonight (Reds vs White Sox, not that it matters). I was using the 200-400 with a Sandisk Extreme IV CF card, freshly formatted and all that stuff. I could not get that camera to fire more than one frame per second. I tried different data cards, I tried it with and without the MB-D10 (with ENEL-4e), but nothing worked. I shot manual, S-preferred, A-preferred, it did not matter.

So, I got home and tried another lens. The 105 macro was sitting there asking to play. Same result. On a whim, I decided to take out the CF card and shoot in demo mode. Presto change-O, then it worked just fine for about 20 frames and played them all back just fine. Both lenses, no issues until I insert a CF card.

Ideas? It's OK to tell me I'm forgetful - I hope it turns out to be a goofy user error.

Thanks!!!
--
Larry
http://photos.apogeeaimhigher.com