[Exim] mail-wrapper error

Hi,

I'm hoping someone has a fix for the below error that appeared today in
my logs:

'Mailman mail-wrapper: [ID 702911 mail.error] Failure to exec
script. WANTED gid 1, GOT gid 8000. (Reconfigure to take 8000?)'

Mailman has recently been installed and configured on a Solaris 8 box
running exim. Test lists have been set-up and seem to behave as expected.

Thanks for any help.

David Smith