unlock memory card?

I downloaded video from my PNY optima 8GB memory to my computer, then tried to delete the video after making a DVD. I did so by dragging everything to the trash, except one file- $RFS_LOG.LOS

When I tried to use card today to record, the camcorder said unlock card. There wasn't anything in the camcorder menu I could find to do this. I have a Samsung SMX-F40BN/XAAS/N