Reformatted the cf card. No luck. Going to run an error check next. If that don't work, I'll just take some of the games off.
EDIT: Just ran chkdsk and it found no errors on the card. I'll try downloading the current version and repatching the dldi. If that don't work, maybe just stick with the previous version.
EDIT AGAIN: Took all but 23 games off - now it works. Go figure.