problem with readfile

Has anyone come across any problems using readfile with php4.0.2 apache module? Basically when a user clicks on a link a page is registering their details then redirecting them to the file using header. Here's the code what I am using Header("Content-Type: application/octet-stream"); Header("Content-Disposition: filename=".$q->f("path")); readfile($DOCUMENT_ROOT."/files/".$q->f("path")); The browser is getting the prompt to download or open the file but all the file contains when you try to open it is ÐÏ à¡± ???? This has worked before using php3 CGI and I think php4.0pl2 Any clues anyone Many thanks for any help M@