I've had this issue twice now in the past week or so when using the K200d. This most recent time (today) I had a fantastic bokeh panorama going of a cop car parked on the side of a street. When I went to review the images in the camera after it said something along the lines of "image cannot be displayed" for several of the pictures. No bokeh panorama, which kinda irritates me because it was a lot of work and I want to know what causes this. The first time it happened I was at the beach shooting some friends and lost about 30 images, each saying the same thing "image cannot be displayed."
It seems to only happen when I take several images in succession, JPEG and RAW dont matter it will still happen. Im not talking a ridiculous amount of images in high-burst mode (which is still only 3 fps) but just taking an image, recomposing and taking another, etc. It only takes about 3 of 4 images before it starts to happen. Than i have to wait for at least a couple minutes for the camera to restore to its old working self becoming essentially a brick until it resumes function.
Im going to try out another memory card tomorrow and see what happens