I too have experienced this... I couldnt quite pick what was happening but
Ive never had issue with Site to Site VPN RDP but when i PPTP in I do get
the black screen issue.

I shall follow this topic with interest since i will primarily be supporting
clients using PPTP and RDP

Thanks,
Jai

-----Original Message-----
From: Olov Nilzén [mailto:olov dot nilzen at gmail dot com]
Sent: Tuesday, 3 October 2006 5:52 PM
To: m0n0wall at lists dot m0n0 dot ch
Subject: [m0n0wall] PPTP MTU


I have a problem with remote desktop-connections over PPTP (all screens are
just black), after some Googling I've come up to that the problem is that
the MTU is to high, is it possible to change the MTU for PPTP-connections?

Regards
Olov Nilzén