I upgraded to Ubuntu 10.10 from 10.04.
90% of the upgrade was ok but my Ubuntu-apache2-postgres-8.4 - mediawiki1.16 does not work anymore.
Is there a bug in the postgres client or in php5 pg?
it is a bug in ubuntu php5
A search of Google revealed that you're not the only one having this issue, but I'm personally not aware of any specific issues. If you're using the machine as a webserver, then you shouldn't be using a pre-release on it anyway. It is much better to use a release that is known to be stable for a webserver.