http://kb.mozillazine.org/File_types_an ... ing_dialog
In certain situations, you may not be able to set an automatic download action because the choice to automatically perform the action for future downloads will either not be remembered or the option will be "grayed-out"<snip>. This problem can occur when a misconfigured web server incorrectly sends the file with the MIME type "application/octet-stream" or "text/plain". It also can happen if the server assigns "Content-Disposition: attachment" to the download [1].
This is a long-standing problem in Firefox, mentioned here:
https://bugzilla.mozilla.org/show_bug.cgi?id=250914
More discussion on the Firefox bugs related to the "do this automatically" option not being grayed-out, resulting in users wondering why Firefox is not remembering their choice to set an automatic download action, can be found in this topic:
http://forums.mozillazine.org/viewtopic.php?t=521648
does not "do this automatically from now on"
schapel wrote:There are some bug reports on the issue already:
https://bugzilla.mozilla.org/show_bug.cgi?id=382987
https://bugzilla.mozilla.org/show_bug.cgi?id=347843
https://bugzilla.mozilla.org/show_bug.cgi?id=331259
https://bugzilla.mozilla.org/show_bug.cgi?id=285976
https://bugzilla.mozilla.org/show_bug.cgi?id=250914
I would still suggest collecting information here first before commenting in those bug reports. There are different issues discussed in the different bug reports, and we should put the information into the correct bug report so as not to further confuse the issue.