Ftp redirect: now files are created but not filled with data

I have a program running on a computer from remote, that downloads a radio stream and uploads it to an ftp server, it works great but recently the guy running the server decided to stop giving out the service to his friends.

I asked him if he could redirect my ftp url to the url of my own server and he did so, however, now every time the client logging the music goes to upload to the server (it uploads about 4 individual songs each time) it will create a file for the first song of the 4, and not fill it with any data, it does this over and over again, creating a "XXX.mp3" file for the 1st of the 3 or 4 songs and not uploading any data to it,

does anyone have any idea why this might be? I made sure that the user information was 100 percent correct, and tested by uploading a file manually which worked.

again the client computer, that is logging and uploading the songs to the ftp thinks its uploading to the site run at the old URL but is being redirected to my url.