issue with pptp plugin

[Trey Nolen <support internetpro net>]

I'm running Ubuntu Jaunty using the network manager package that comes
with the distro.  It is version 0.7.1~rc.4.1-0ubuntu2. The
network-manager-pptp package is version 0.7.1~rc.4.20090316
+bzr23-0ubuntu3.

My PPTP VPNs get connected fine and traffic passes just like I want it
to. The problem is that the VPN drops shortly after I'm connected. It
seems to have something to do with the AMOUNT of traffic that goes
through the VPN.  For example, I can ping a machine on the remote
network for a good while without dropping the connection, but if I bring
up a remote desktop session, the VPN will almost immediately drop.  If I
log into, for example, the web interface on a router of the remote
network, I can usually browser to two pages before the VPN drops.   

When the VPN drops, I get a "VPN Failed" notification in the Gnome
notification window.  It is almost like the VPN never FULLY establishes.
The "VPN Failed" window is the same one I get if the VPN never connects
at all. 

I'm using pretty much the stock options when creating the VPN, with a
few exceptions: I specify a route for the remote network. I check "Use
this connection only for resources on its network". I disable EAP
authentication. I enable MPPE encryption and allow stateful encryption
(have tried that both ways).

If anyone has any ideas on how to get this functioning better, I welcome
them.  

Thanks.

Trey Nolen