http://support.mozilla.com/en-US/kb/Managing+file+types
When you click a link to download a file, the MIME type determines what action Firefox will take.

If the MIME type is mis-configured on the server where that file is being downloaded from, or is absent and a generic MIME type is being sent - Firefox will default to asking you how you want to handle that download. Firefox won't guess based on the file extension, like other browsers might (IE), Firefox lets you determine how that file is to be handled.

I understand what you have said, but that is not the problem I am facing. Please re-read my post.

Do you have an example web page and download hyperlink where you have that problem?
What file types are involved?

It's far easier to see what causes a problem with a specific download link or action than it is to speculate about a general situation.

It happens with every .torrent file and every .nzb file from any site.

I understand that FF relies on the MIME-type on the site, but this is rarely used as far as I can tell, and it's annoying.

Is there a way I can force FF to just use the file extension like maybe IE. It's a type of guessing I'd call function.

I agree with Biggles, how can we make Firefox use extensions?

Obviously there are many flaws when relying on MIME-types.

I have this same problem every time I try to open a word, excel, and pdf document. I agree that FF needs to use extensions, not MIME-types.

http://revision3.com/filmriot/episodes large. mp4

I have finally found a solution! Just download and install this addon named mime_edit-0.601004242000.xpi and add your MIME types, e.g. RAR, AVI, WMV.... http://space.geocities.yahoo.co.jp/gl/alice0775/view/20080912/1221150790 This one is compatible with Firefox 4

The site: http://space.geocities.yahoo.co.jp/gl/alice0775/view/20080912/1221150790 is completely down, or at least I cannot access it.

I have FF 3.5 and would love to get hold of the MIME Edit add-on somehow.

The-Edmeister have you still got a copy of the one for FF 3.0.* + 3.7.* ?? If so could you or anyone else that still has a copy upload it to a bitlocker and send the link here?

I would also like to try this out on the latest FF 4 but am not sure if alice0775 did have one up for that version. If he/she indeed had an MIME edit FF add-on for 4.* would you The-Edmeister or anyone else that has this great add-on upload it to a bitlocker and post the link here as well?

That would be tremendously appreciated. Unfortunately the site seems to have gone off-line completely just recently and this MIME edit add-on for FF seems a real hard to find gem.

Thanks for any help towards this. Tried editing the .rdf file manually but not sure what to write exactly. Any ways, thanks for any help.

Well if anyone has it upload it please. Thanks, that would help a lot.

I've stumbled upon an extension that fixes this bug. Here's the site: Fixing Firefox's "Do automatically checkbox"

And here's the extension (it's still experimental but it should work). Tested on Firefox 5.0.0.1. Win7 x64

https://addons.mozilla.org/en-US/firefox/addon/web-page-fixer/

I hope it works for you too. ^^

I haven't tried the above add-on but the InlineDisposition add-on was created exclusively to fix the "do this automatically..." problem.

https://addons.mozilla.org/en-US/firefox/addon/inlinedisposition/

Bummer that this stupid annoying problem still persists. The good news is there are two solutions, fixes, or workarounds. The addon Webpage fixer: web page fixer Totally solves it for me. Another one, that seems to work as well or perhaps better is inline disposition Webpage fixer gives additional options besides fixing this annoying issue. Inline simply tries to force Firefox to render whatever it can in the browser first, if that fails, it automatically opens the file in an external program (as designated in the preferences/applications tab.

I've tested them both on firefox 12.0 in Linux Debian x64 (Crunchbang - modded to use Xfce 4.8) and they both remove this rather annoying little chronic firefox bug.

Peace