Make sure that you haven't set a page that plays the file as the home page. *https://support.mozilla.org/kb/How+to+set+the+home+page - Firefox supports multiple home pages separated by '|' symbols You can also check the download manager for unfinished files. *https://support.mozilla.org/kb/Downloads+window ----- It is also possible that there is a problem with the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder. Delete the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox Profile Folder. *Help > Troubleshooting Information > Profile Directory: Open Containing Folder *http://kb.mozillazine.org/Profile_folder_-_Firefox Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost, so you will have to create them again (make a note or bookmark them). See also: *http://kb.mozillazine.org/Session_Restore *http://kb.mozillazine.org/sessionstore.js *http://kb.mozillazine.org/Multiple_profile_files_created

Where is this "Music" from? youtube? OR somewhere else? Try to upgrade to Firefox 13