can't write to sd card

[astod]

I'm copying mp3 files to a sd card. After I get about half of the card used
up, I start getting the message "Cannot copy-- the file or directory cannot
be created". I've tried 2 different cards and the same thing happens. help.
thanks

 

[Alan Edwards]

Try copying into folders. I suspect you have more files in the root of
the drive than it can take.
How many files are you copying before you get that message?

....Alan