YSmenu help

Hi, I just tried YSMenu today on my R4, and I've run into a problem. At first, there was no issue playing games, but now, only 3 or 4 games show up on the list. Additionally, when I checked my SD card, I found that there were 3 strange files named "@", "@", and "@@@", which I cannot move, copy, or delete Has anyone else run into this problem? If so, could you tell me what you have done to fix this issue?
Thanks,
Shenaynerz :)
p.s. i used this method when installing YSMenu, if it helps: http://forum.romulation.net/index.php?topic=36273.0

Weird files showing up on your MicroSD can be a sign of corruption.You should backup the files you can (copy them to your computer) and format your MicroSD.
Use this program to format your MicroSD correctly.
http://www.sdcard.org/consumers/formatter/