I've got a problem whit my (4GB) MicroSD. I wanted to erase all the files on the SD but when I try to delete several it says Error code -43. How can I delete these files?

Some info:
-The files have some strange names like ú%7è.ïúu and I also can't change the names of the files (Also Error code -43)
-I also can't open these files (Also Error Code -43)
-I can't open the info screens of these files (No error code)
-When I drag them to the trashbin they are gone, but when I select the MiscoSD again they're back. This also happens when I try to open the Info screens of these files, there gone and then they are back...
-The files are 0kb (nothing?)
-And it's not a virus (I've also scanned them)

Anyone got a solution to this problem?