PPTP connections from single static ip kicking off

We are currently connecting to a terminal server via PPTP connection from a single static ip. The firewall my office uses is a Juniper Netscreen SSG20. The office we connect to uses a Cisco PIX. We are having an issue of multiple connections being needed, but only one person in my office can connect at a time. When the second person logs in, the first person’s connection is dropped. Both locations use T1 and single static IPs. Is there a setting in the Juniper or in the PIX that can be changed to allow more than one PPTP connection at a time?