[Samba] Is there a way to enforce a single login domain wide

[Douglas Phillipson]

I would like to enforce a policy for a user being only able to login 
once anywhere in the Domain.  When you use roaming profiles, the system 
gets confused and leaves the local profile on the client PC if the same 
user logs in on a second machine while they are still loggewd in on the 
first one.  This then causes the Samba profile to NOT get updated on 
logout.  If a user is currently logged on a domain, I need that user to 
be refused if they logon to a second machine until they logoff the first 
machine.  Is this possible with Samba, or would I use some sort of logon 
script to query something and force the user off at their second login 
attempt?  When this problem occurs you have to reboot the machine and 
remove the users local profile so it will again use the roaming profile 
on the samba DC.  Very irritating...

Thanks

DSP