You will be slightly behind if you use Linux and their own version of Firefox instead of the Mozilla standard version. (Not of course standard in some Linux distros)

I use Ubuntu, and their Canonical Firefox Aurora just updated I think yesterday from fx15 to fx16.
{Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:16.0) Gecko/16.0 Firefox/16.0 ]

I also have the Mozilla Firefox Release 64bit and that updated as expected a while ago from fx13 to fx14.
{Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20100101 Firefox/14.0.1]

Not sure why fx13 is not updating for you.

Maybe something to do with your distro IF it is their version. IIRC some early Ubuntu LTS versions probably did not update Firefox. But you may have the Mozilla version as your system info aside shows
User Agent Mozilla/5.0 (X11; Linux i686; rv:13.0) Gecko/20100101 Firefox/13.0

You could just download the latest version from

• http://www.mozilla.org/en-US/firefox/all.html

Just take care not to delete the existing firefox profile, preferably back it up first just in case.

• back up and restore information in Firefox profiles

No, I'm not using the one provided by the distro. I'm using (and have been for quite some time) the download from mozilla.org.

yes, I certainly could just manually update it (probably will) but I'd still like to figure out why it stopped updating itself.

Yes I like to find the reason for problems. I am then more confident they will not re-occur, or that I am not overlooking something else, that may be more serious.

Try resetting the update, by deleting the installation files "active-update.xml" and "updates.xml" maybe it is just some one off glitch. For that and other suggestions see

• http://kb.mozillazine.org/Software_Update#Software_Update_not_working_properly

John: thanks again for following up.

I gave up and manually updated later yesterday, so for right now I can't pursue it. next time an update occurs I'll try those suggestions, and will attempt to remember to post results here.

Make sure you have read/write permissions for the Firefox folder as a easy way around this is to have Firefox in a folder in /home/

If you do not have write permission the the Firefox installation folder then Firefox should display an "updates available" message if you check for updates in Help > About.

You may have to update manually and download and install the full version.

OK, now that F15 is out, the same thing is happening. Oddly enough (and this may or may not be significant) of all the Linux systems I use, the only two that so far won't udpate are both Centos-5 systems.

I've tried removing the two xml files as suggested above without success. Specifically, on both those Centos systems, I've removed both xml files mentioned and restarted firefox. It still says it's 14.01 and is up to date.

On my home desktop I removed all the subdirs containing any previous version and reinstalled 14.0.1 afresh, but no change, it still won't update.

there appears to be a bunch of detritus still on the system from the original firefox installation(s) that are a part of the Centos system (though I've suppressed the ability of Yum to install any further updates). Do you suppose that something is still finding some of those older files even though my manual installs are NOT in the same folders/paths? To this end, I note that even though it won't update, it says it's on the "release channel", which is correct (according to the channel-prefs.js that is part of the 14.0.1 installation).

any further ideas?