WEP and WPA on the same network - problem getting an ultrasound machine to work

I own a vet clinic and we have a network, mostly wired but also a WPA wireless network.

We recently bought an ultrasound machine. It only supports WEP!

So I want to use a WGR614L to make a WEP network and connect it (using the 'Internet' port on the back of the WGR614L) to rest of the network. I need the ultrasound software running on the server to be able to 'see' the ultrasound unit.

Here's the setup:

192.168.0.1 - main router (connects to our DSL service) - it's a Netgear DGN2000
192.168.0.2 - server with the ultrasound software

192.168.0.52 - 'Internet' interface of WGR614L. connects to our main router 192.168.0.1.
192.168.1.3 - Ultrasound machine, connected by WEP to the WGR614L

I thought by telling the ultrasound software on the server to look for the ultrasound machine at 192.168.0.52 it would work, providing the port-forwarding was set up. But it doesn't. I even tried making 192.168.1.3 a DMZ! But it still doesn't work.

I've spent several hours on this, without success. The ultrasound unit itself is fine, because if I make my laptop part of the WEP network and install the software on it then it sees the ultrasound unit.

The idea is that the ultrasound user can save ultrasound images to our main server 192.168.0.2, and since no one else will be using the WEP, i can lock it down.

I'd really appreciate some help!

thanks,