Exiting certain CF folders crashes my MPC

When I go into certain directories/folders on a CF card, e.g. ROOT/CHOP/PIANO/ALRITE, and try to return from there to the root directory, my MPC 2000xl (OS version 1.2) crashes. It crashes every time I go into that folder and exit again. So far I've had this happen with two different directories (the above mentioned ROOT/CHOP/PIANO/ALRITE and ROOT/CHOP/GUITAR/ANNA). I've had the GUITAR and PIANO folders for at least a couple years, and I never had this problem before. Yet now the MPC crashes with two separate folders within four days?? Something's not right. Using another CF card isn't really a good option since I got this one set up just the way I want it.

Any thoughts on what could be behind this?? Thanks.