In my D200, I use Lexar Platinum II 80X 4GB cards. Also, I use Lexar Platinum II 200X 8GB cards. Never had a problem with them.
And like jdeg said, update your firmware to the latest, which is A 2.01 AND B 2.01. Follow instructions EXACTLY! It's easy to do. Let us know how it turns out for you.
Oh...one other thing to mention: remember to always reformat your card IN CAMERA when you're done downloading your photos to your computer. Very important!