Comment 6 for bug 207029

Regarding Alexander Sack's instructions to reinstall, I found that this worked ONLY IF I closed Firefox first.

With Firefox closed, "sudo reinstall firefox-2" works:

Setting up firefox-2 (2.0.0.14+2nobinonly-0ubuntu1) ...
Please restart any running Firefoxes, or you will experience problems.

Processing triggers for libc6 ...
ldconfig deferred processing now taking place

--------------------

When I previously left Firefox open, it continued to fail:

Setting up firefox-2 (2.0.0.14+2nobinonly-0ubuntu1) ...
Please restart any running Firefoxes, or you will experience problems.
cp: cannot stat `/usr/share/firefox-2/firefox-2-restart-required.update-notifier': No such file or directory
dpkg: error processing firefox-2 (--configure):
 subprocess post-installation script returned error exit status 1
Processing triggers for libc6 ...
ldconfig deferred processing now taking place
Errors were encountered while processing:
 firefox-2
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install. Trying to recover:
Setting up firefox-2 (2.0.0.14+2nobinonly-0ubuntu1) ...
Please restart any running Firefoxes, or you will experience problems.
cp: cannot stat `/usr/share/firefox-2/firefox-2-restart-required.update-notifier': No such file or directory
dpkg: error processing firefox-2 (--configure):
 subprocess post-installation script returned error exit status 1