Minefield 3.6a1 segfaults after leaving page with java applet

[Zorael]

I'm running Minefield 3.6a1 from the Ubuntu Mozilla Daily ppa, and
it's been stable so far with the sole exception of java applets.

As soon as I leave a page with java content, the browser crashes and
reports a segfault to the terminal. There's no other debug output, but
it's very consistent to java applets, and 100% reproducible with
http://javatester.org/version.html. Just open it and then close its
tab.

This is on a Jaunty system, running Sun's java plugin since the
OpenJDK/Icedtea one doesn't work (other bug;
https://bugs.launchpad.net/ubuntu/+source/openjdk-6/+bug/344705).


$ apt-cache policy firefox-3.6
firefox-3.6:
  Installed: 3.6~a1~hg20090404r26915+nobinonly-0ubuntu1~umd1
  Candidate: 3.6~a1~hg20090404r26915+nobinonly-0ubuntu1~umd1
  Version table:
 *** 3.6~a1~hg20090404r26915+nobinonly-0ubuntu1~umd1 0
        500 http://ppa.launchpad.net jaunty/main Packages
        100 /var/lib/dpkg/status


$ apt-cache policy sun-java6-plugin
sun-java6-plugin:
  Installed: 6-13-1
  Candidate: 6-13-1
  Version table:
 *** 6-13-1 0
        500 http://archive.ubuntu.com jaunty/multiverse Packages
        100 /var/lib/dpkg/status


Largely irrelevant, but for posterity:
$ uname -a
Linux lethe 2.6.29-02062901-generic #02062901 SMP Fri Apr 3 14:17:44
UTC 2009 i686 GNU/Linux