exim 4.69 freebsd 7.0 locking issues

[Andrew]

Hi all,

Running Exim 4.69 on 7.0-RELEASE-p6 FreeBSD.
The box has been recently upgraded from 6.3 (like 24 hours ago).

Currently Exim is sending the following lines to the log files.

2008-12-01 19:02:35 Failed to get write lock for 
/var/spool/exim/db/callout.lockfile: Invalid argument
2008-12-01 19:02:35 Failed to get write lock for 
/var/spool/exim/db/callout.lockfile: Invalid argument
2008-12-01 19:02:35 1L74Cp-000GRN-3R Cannot lock 
/var/spool/exim/input//1L74Cp-000GRN-3R-D (22): Invalid argument

The permissions are all correct for the spool directories and for Exim 
itself.

It is creating stacks and stacks of 0 byte files in the message spool 
directory.  I have recompiled all the ports but to no avail.  I've 
upgraded 2 other machines with 99.0% the same setup with no issues.
The only difference is hostnames/ips and that this machine is running 
mysql on it. Everything else on the machine (spam-assassin, clamav, 
mysql) is working fine.

Has anybody got any ideas, other than downgrade back to fbsd 6.3?

Cheers
cya
Andrew