mostin wrote:
When the 512mb card is full, I get a message saying it is full. On the 2gb cards, I get a message that says "the file cannot be created". Any ideas? Thank you.
That difference in messages is the clue IMHO. I expect that you are putting the files into the root directory of the card, and that the filenames are longer than just 8.3 characters. The 2GB card is probably FAT16 formatted (which is the normal spec for a 2GB SD card) and you're running out of root directory entries on the 2GB card, since long filenames use more than 1 directory entry per file. This article from MS describes the issue:
http://support.microsoft.com/kb/120138To prove or disprove that theory, make a subdirectory on the card and copy your music onto that. If you can copy many more files into that subdirectory, then this was the problem.
So either use a subdirectory for your music files (if your MP3 player can use files in a subdirectory) or format the SD card using FAT32 (if your MP3 player can use that format) since FAT32 doesn't have that same limitation of files in the root directory. If your MP3 player can't use either option, then the only other way to fit more files into the FAT16 root directory, is to limit them to the 8.3 filenames described in that article.
Good luck