serving up blobs for download

This isnt exactly a PHP question, but... I want users to be able to download (not view with a viewer) pdf files which I have stored as blobs in MySQL, so the php script reads the blob into a variable, then does this: header("content-type: application/octet-stream"); header("content-disposition: filename=$filename"); echo $blob; With Netscape, this works great, the file save box opens and the filename to save as defaults to my variable $filename. The problem is that IE thinks it should be able to find a program to "view" the content-type of application/octet-stream. Netscape defaults to downloading unknown types, IE just gets confused. Does anyone know how to handle that problem? Is there some other content-type which is specifically used for downloading? Thanks, Rob