OK, finally got monowall set up using an x-modem. I'm using the modified 
image.

It all works fine except the WAN connection seems to time out after a 
while, DNS is not available (except for local) and the only way to get it 
running again is to release the DHCP lease on the WAN interface and renew 
it again.

After that everything springs to life, why is it doing this?

The dhcp lease on the x-modem is very short so I don't see why I have to 
manually release it.

Any ideas?

Cheers

Steve