Trend PC-Cillion 2004 Firewall

I have noticed that the firewall with trend Pc-Cillin Internet Security 2004 is blocking traffic with my NTL cable modem. I used to use Pipex ADSL and the account is still active. I have found that the ADSL account will send files when the NTL account won't. By moving the firewall to a lower security setting I get the files sent via NTL however so it is clearly a clash. What settings do I need on the exception list if my firewall to allow normal cable modem traffic on NTL? I have permitted in/out setting for web service (http) on port 80, send mail (smtp) on port 25 and receive mail (pop3) on port 110. What other settings does a cable modem need that my ADSL didn't? Thanks for you help.