Oops, looks like I've smoked something bad. I believe I didn't actually restart firefox after the upgrade (had one copy still active) and had some corrupt state somewhere when the error occured.
I just existed another firefox window, and restarted firefox. This time, unlike in the first time, it opened on the local 'About Kubuntu' page: file:///usr/share/ubuntu-artwork/home/index.html Hinting that the upgrade was actually in effect. And the 'Help -> About Firefox' is working just fine. Sorry for the spurious report. Please close/ignore. Thanks! -- Firefox 1.5.0.8 'Help->About Firefox' seems broken https://launchpad.net/bugs/72809 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs