Greetings - We use a webmail (Squirrelmail) client that a user's webbrowser can connect to to view email. On Fedora Core 7 and Firefox 2.0.0.14 when a mis-MIME-typed (application/octet-stream) PDF file was selected a pop-up box appeared that had options to cancel, save or open the file. With Fedora 11 and Firefox 3.5.3 when I select the same PDF I only get the option to cancel or save. I attempted to make a change to my mimeTypes.rdf file to give me the option of viewing the file. I used the following webpage (http://www.mozilla.org/docs/end-user/helper-applications.html) along with some targeted websearches to come up with the following: ... I do get the notice that the application/octet-stream-typed PDF is a 'TonyTest PDF document'. But I still only get the option to cancel or save. I did find two different extensions that may help: 'Open in Browser' and 'OpenDownload'. But the person I am attempting to help, a man with the first name of 'tenured professor', may still find them a little difficult/confusing/annoying. I will attempt to train my constituent in using one of the two Firefox extensions. But if possible a cleaner method would be to change a local configuration file (like mimeTypes.rdf) to react to the extension and not the MIME-type. Tony - == This happened == Every time Firefox opened == We upgraded from FC7 (Firefox 2.0.0.14) to F11 (Firefox 3.5.3)