Bug#490801: apache2-mpm-prefork: mod_dbd /w mysql support gives: [error] (20014)Internal, error: DBD: failed to initialiseIt

[Stefan Fritsch <sf@sfritsch.de>]

It works for me with 2.2.9-3, and there is no difference to 2.2.9-2 
that should affect mod_dbd. You could try

- disabling mod_security 
- strace'ing apache to see what goes wrong

Cheers,
Stefan