After upgrading to Ubuntu Feisty, pam-based password authentication for Apache (2.2) didn’t work anymore. In the logs I found only some very useless entries like [Wed Apr 25 20:36:20 2007] [error] Internal error: pcfg_openfile() called with NULL filename [Wed Apr 25 20:36:20 2007] [error] [client xxx.xxx.xxx.xxx] (9) Bad file descriptor:…