add two to the group, only one shows up?

[Gary Turner <kk5st@swbell.net>]

I added myself (gt) to my dialout group.  Simple enough.  When I ran
'groups' dialout was not one of gt's groups.
So I added my other user (garyt) to my group file.  su to garyt and run
groups and there he is.  su back to gt, run groups -- not there.  Back
to root, edit file reversing the order of the users (thinking to expose
a syntactical error).  All to no avail.  garyt can join the group and gt
can't.

Can anyone shed any light on this?

--
gt
Yes I fear I am living beyond my mental means--Nash