samba - Apr 2007 - changes to /etc/group without restarting samba

I'm running samba 3.0.23 on red hat fedora core 6 with kernel
2.6.18-1.2849.fc6 (64-bit). I'm implementing a framework where new
directories are added in an existing samba share with corresponding
entries in /etc/group and am trying to restrict access to those
directories to only users in that group. The clients connecting have
user accounts on the samba server (there are no corresponding windows
groups).

If I add users to these new groups and have been previously connected
as one of those users, I am not able to access the newly allowed
directory (with the user being a member of the group, but not the
owner and permissions of 770 on the directory) unless I restart the
samba processes or disconnect/reconnect. Is there a way around this
problem without having to restart samba or having clients
disconnect/reconnect?

Thanks for any assistance.
Jeff Nathanson