exim4 behaves strange

[Michael Przysucha <mp@abi-2k3.net>]

Hello,
I have a problem with my exim4 deamon. It is configured to relay with SMTP-Auth. Yesterday everything was fine but 
over night the following behaviour started to occur with every message:

2005-12-29 11:53:52 no host name found for IP address 192.168.1.1
2005-12-29 11:53:55 1ErvPv-0000JF-9A <= mp@abi-2k3.net H=(mp45) [192.168.1.1] P=smtp S=961
2005-12-29 11:53:58 Start queue run: pid=1192
2005-12-29 11:53:58 1ErvPv-0000JF-9A Spool file is locked (another process is handling this message)
2005-12-29 11:53:58 End queue run: pid=1192

The Mails will not be sent even if they are within the pool for over 5 hours! does anyone have an idea what is wrong? 
Config-file and username/pw for relaying are ok!

Thanks in advance,
Michael Przysucha
(Germany)