This is a side-effect of bug 98360, which forces Mozilla to prompt the user to download an attached file (which has Content-disposition: Attachment in its HTTP Headers). Since the Helper App dialog is displayed every time, the "Always ask before opening this type of file" line+checkbox is useless in this case, and should be removed. It only confuses the user.
15 years ago
Marking dup of same bug assigned to someone who is actually planning to work on it... *** This bug has been marked as a duplicate of 193698 ***