samba - Oct 2003 - is there a way to enforce a single domain wide login

If I put a preexec script in the [profiles] share that touches a file in 
the users home dir, then removes it with a postexec script, I can 
enforce a domain wide single login.  That is for about 1 minute.  What 
appears to be happening is the share has a timeout feature that 
disconnects after about 1 minute and then calls the postexec script 
which removes the file required to determine if that user is currently 
logged on.  I tried using the "deadtime = 0" attribute but it still 
times out and runs the postexec script.

Any suggestions are appreciated...

DSP