I have integrated SWFUpload into my CMS and it has been working perfectly. But I just recieved an email from a user who is getting a 403 upload error. I modified the javascript function "uploadError" to simply alert the "message" variable and all that is returned is "403". Any ideas??

The folder being uploaded to is chmoded to 777, file uploads are enabled (PHP 5), and I cant really think of anything else that might prevent it from working.