PPTP problem with Netgear DG834G

We have a branch office in Scotland who connect to our main office
network using the Windows VPN software.

But the connections seem to be very intermittent - for example; User 1
and User 2 will be able to connect without any problems but User 3 will
get Error 721 when trying to connect. The following day Users 1 and 2
may get Error 721 but User 3 is able to connect without any problem.

Our VPN server here is ISA which is directly connected to the Internet.

I'm wondering if there is perhaps a maximum number of PPTP connections
allowed through the Netgear router? Does anyone know if this is the
case?
--
Stoneskin

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