3Com problems with internet sharing

I just installed a 3com officeconnect 8 port hub (3c16750B) and an officeconnect cable/dsl gateway (3cm-3c855), and presently there is no DSL connecting, but soon will be in the future. For now however, we were configured for internet sharing through a win2000 computer, with 4 windows 98 computers and an xp machine connecting to a dialup line from the 2000 computer. Once we put the gateway on though, all the computers lost the ability to connect to the windows 2000 computer for internet sharing. They can all see each other on the network through network neighborhood, and file and print sharing is working, but the internet sharing is not. We had a dedicated ip address on the 2000 computer for the others to connect to via the IE proxy settings, but since the gateway is assigning ip addresses now, this ability is gone. Is there any way that we can continue the internet sharing with this gateway still connected, at least until we have dsl installed?