Originally posted by DeadJohn I don't know what's causing your problem, but here's a detail that might help you understand what's happening. PEF and DNG both contain an embedded JPG preview. Sometimes, the main image gets corrupted while the preview portion is okay. When you first import and view the image it might look good because the JPG preview is being used, but as soon as your software tries to read the main PEF or DNG the corrupted portion shows. I have seen similar problems in Lightroom.
Intermittent problems likes this are difficult to troubleshoot. Possible sources of the error are: memory card, camera, memory card reader, software.
Thanks for the input DeadJohn. I have had the problem with two freshly formatted cards. It has occurred on three or four different apps. It occurs whether I import through the camera or the sd card slot. I think I'll be visiting the camera store tomorrow as foto guy suggested.
Thanks,
Tony