Kubuntu 12.04 Firefox and Rekong don't know how to open downloaded files

[MountainX]

I just installed Kubuntu 12.04 beta 1.

Both Rekong and Firefox don't know how to "Open Containing Folder" for downloaded items. They also don't know how open the item itself.

Furthermore, if I manually tell Firefox (in the dialog) to remember the file associations, that creates a new problem. Every file opens in Dolphin first, then Dolphin opens the correct application.

Here are the steps to reproduce this.
1. boot up into a Live CD.
2. change software sources to enable downloading packages
3. install Firefox using the menu item under Main Menu > Internet > Firefox installer
4. open Firefox after it finishes installing
5. download and save any file. I tested with a PDF.
6. open the downloads dialog (Firefox > Tools > Downloads)
7. right click the downloaded item and choose Open Containing Folder.
[8. for many file types, attempting to open the item from this Downloads dialogs, such as opening JPEG, will produce the same issue.]

Expected result:
Firefox should know to open the folder in Dolphin.
It should also know how to open various types of content with the correct application (i.e., using mime types).

Actual results:
Firefox does not know how to open the folder. Dolphin is not even suggested as a default option.
Firefox also doesn't know how to open most file types.
Rekonq has the same (or similar) problems.

This issue is present in both an installed system (64 bit via Alt installer) as well as a Live environment from the DVD.

Possibly relevant:

In Firefox preferences > Applications, the only content types shown are irc, ircs, mailto, podcast, tar file, webca and webfeed. Normally, there would be many more.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/953700/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Paul White (paulw2u)]

Thank you for reporting this bug to Ubuntu.

Ubuntu 12.04 (precise) reached end-of-life on April 28, 2017.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.

Paul White
[Ubuntu Bug Squad]

[Launchpad Janitor (janitor)]

[Expired for Ubuntu because there has been no activity for 60 days.]