mentor 11g 4 port adsl router MR4CWG/uk

Help... I can't get this machine to run more than 1 wireless connection at a time.... when auto issuing IP addresses it is issuing and releasing addresses ok, i have tried long and short lease settings, but when it issues one to a new connection the pc already connected stops having access and reports limited or no connectivity.

I then tried setting all the IPs manually but same result, they all connect individually but only one at a time.

the tech info, limited as it is, about the device says it supports up to 45 connections buti cant get it to support more than 1.

anyone got any more ideas? i suspect a setting somewhere on the conexant hasbani software but i cant spot anything wrong