Something happened to my NES emulator?

Well a few days ago I was putting some ROMs on my fceugx NES emulator. Suddenly something happened and I have no idea what it was. It exited and when I open the folder from my SD card, all the folders are in some really weird text and it says the total size of the folder is 30gb. So I tried to delete it off the SD card from the Homebrew Channel and the Wii froze; When I try to delete it by putting my SD card in the computer it says "Cannot delete file: Cannot delete from source file or disk." It doesn't seem to be affecting anything, but I would like to remove it so I can start over and hopefully get it working. Any suggestions as to what I should do? Thank you.

I had something similar happen to me with a Card... it was a Memstick Duo Pro. It said total size 20+ gigs, all these wierd ass file names and folder names that i couldnt delete. it turned out that the card was a fake one. it looked like the real thing sony logo and every thing but the serial number on the back gave it away that it was indead a fake one. you could possibly have a fake card. i dont know how to check a SD you could google it. again it might not have anything to do with your issue, but it sounds the same.

Check the SD card for errors from properties dialog (tool tab). Check both boxes.

Thank you so much Phoenix, that is exactly what I needed to do.