Problem with K-M 7D

After 27 months my trusty Minolta 7D is giving me my first problem. In instant playback with aperture priority (A) shooting RAW&JPEG my instant playback only shows thumbnails. If I shoot in program mode (P), I get my desired playback, i.e. picture with info and histogram. I'm using a 2 gig Sandisk Extreme III but I tried using other cards and that doesn't make ay difference. Any ideas?
BTW, I know the camera is getting close to it's "best by" date (at 6 megapixels) but it produces lovely pictures up to 13"x19" for me and until Sony actually ships the replacement they showed at PMA, it will remain my mainstay as I have 8 lenses for it.