I have encountered this problem recently when i installed a 3.6.3 version of firefox. When I try to download any mp3 songs from certain sites such as beemp3.com, firefox doesnot allow me to download. The download window containing "Save File" and "Open" is not seen and a new black window appears and the song that is to be downloaded plays in the background of same new black window. But however firefox has allowed downloading data items. The only problem I have encountered is in downloading mp3 files. And the same version of firefox downloads the mp3 in my friend's laptop. please help..