Running m0n0wall 1.11 as a PPTP server.

I can connect from 3 different machines but only one has access to the
LAN behind m0n0wall, i.e., I get an IP address in each case.

Machine #1 works.  Win2k.  This machine can also make a connection to
another Windows PPTP server in a different network.

Machine #2 doesn't work.  WinXP.  This machine doesn't have the
opportunity to try to connect to any other PPTP servers.

Machine #3 doesn't work.  FreeBSD 5.3 running pptpclient.   This machine
can successfully connect to a Windows PPTP server on a different network.

Since all three can connect, is there anything I can look at as to why
two can't do anything once connected?

Scott