Bad CF card or camera problems?

I just purchased a PNY 2GB 266X Compact Flash card, and noticed that every now and then I get shots that get some weird noise in the very same spot:

And another shot on a different day, same card:

Both photos were taken with my Tamron 90mm lens. Has anybody experienced this problem? Card problem, camera problem, lens problem?

It's usually the last photo of a batch.