File Not Found Errors

Hi,

After uploading and saving a mp3 using the Audiofield, the page and player is displayed correctly and the mp3 plays fine. But when returning to this page, the WP Player is displayed but I get a "File not found" error when trying to play the mp3 again. I have created a folder called mp3 in default/files/ and the files are saved to this location ok, the player cant seem to find it though. All user permissions are set correctly.

Thanks for your help.