exim giving 'group mail not found' error

["Mark Hughes" <mark@revmachine.com>]

Hello, I have three boxes all with Apache, PHP, MySQL, and Exim running.

Two of the boxes work fine and the php mail function that calls sendmail
through exim works fine. One box though gives the error:

2004-08-09 03:32:26 Exim configuration error
  group mail, referred to in line 213, was not found

This group is present in my system, the configuration appears to be the same
on all three systems(I set them up all at the same time), and the
permissions for the group mail are all set the same for the directory
/var/spool/exim.

I have tried searching google and have not found anything......

I also searched the archives of this list and found :
http://lists.debian.org/debian-user/2004/07/msg01406.html
but no answer.

Can someone please point me in the right direction on this problem?

Thank you