Our networking group recently implemented a SLL VPN solution using NAT. Almost immediately we began to recieve support calls from clients who were getting randomly disconnected from their mapped network drives. (The network drives are hosted on a NetApp NAS device which shares out data as if it were a 2003 Server. The clients connect mainly from XPand [a few] Windows 7 workstations via a 2003 DFS server. During our troubleshooting, we found this article which seemed to explain our problem: http://support.microsoft.com/default.aspx?scid=kb;en-us;301673 We did some testing and seemed to confirm this is the root cause. With two Win7 clients we were able to consistently knock each other off the file share simply by mapping a network drive. Using Windows XP we were not able to duplicate the behavior as consistently, but it still exists. We attempted to block Port 445 at the VPN device, to force connections to use Port 139. However, the testing group reports this introduced a whole new set of problems, especially time-outs and connection errors. Naturally, we would like to continue to use Port 445 since we would like to get away from dependencies on NetBIOS. The article I linked to says the registry key doesn't have any affect on newer operating systems, so I don't think that will be a good solution for us long term. Anyone have any solutions / ideas they would like to share?