Comment 36 for bug 548866

Confirm the bug is still there:

$ grep middle /usr/share/xul-ext/ubufox/defaults/preferences/ubuntu-mods.js
pref("middlemouse.contentLoadURL", false); // setting to false disables pasting urls on to the page

$ dpkg-query -W firefox
firefox 11.0+build1-0ubuntu0.10.04.2