Sorry to bring such an old thread back to the front.
I followed all of the php5-common removal steps and am still facing numerous removal failures (with --purge remove, --reinstall install, autoremove). I did edit (nano) /var/lib/dpkg/info/php5-common.postrm .This is preventing other applications from updating because it somehow, even when I select just one update to perform such as modrana, moves itself to the forefront and prevents upgrades of other applications as well as apt-get dist-upgrade from working. Feel free to tell me what you would like for info and I am happy to provide it (so long as it is not private and identifiable to a person/device).
Thank you,
David

P.S. I did write to the "Author's" email address but because it is Ubuntu Developer and I (clearly) played no role in php, they rejected posting as much and stated I should post it here. Because this thread already exists, it did not appear to make sense to create a new thread.