Email enabled group members were removed but came back

[bktbo]

Last week we cleaned up an email enabled security group, removing all individuals and adding various groups. Today all the individuals are back in the ACL (as well as the groups). I haven't had luck searching so I'm hoping someone here knows what would cause this.

A couple points....

I found a link off msfn discussing how a distribution group can turn into a security group if added to a public folder access list. I do not know if this group was first created as a dist group.

This does not appear to have been a query based group though my understanding is "query based" is only relevant for distribution groups.

Three admins here and no one made the change. (??)

There are no scripts running in the background that I know of.

We have a blackberry server and a goodlink server.

Exchange 2003

AD 2003 native - single domain

Thanks for the help everyone!