Comment 3 for bug 305254

@Krenar Qehaja

When you did the upgrade, I assume you choose to keep your php.ini:s instead of installing new versions of it/them?

The problem arises from the fact that Hardy loads mcrypt.so directly from php.ini while Intrepid has it included from conf.d/. Keeping the original php.ini from Hardy, while the php5-mcrypt of intrepid adds itself to conf.d/ causes the situation you describe.

Actually, this affects mod_php the same way. The warning shows up, by default, in /var/log/apache/error

Not sure whatever to classify this as an upgrade-bug or not.