ICS with a Broadband connection

ICS won’t work with Broadband connection:
I have a crossover network with a Win98 client and a WinXP server that worked beautifully using a dialup modem connection. However after adding a DSL external modem by Bell when I reconfigure to use it everything looks good but the client cannot get email through Outlook Express (it sees the mail but times out and can’t access it).
Also the client can only reach CERTAIN web sites?? Go figure. The client is setup to get IP address automatically and the server is running DHCP I think. Would adding a hub and rewiring be necessary? Any help would be appreciated.