[hugh]

All I can say is that my Primus connection works fine so if its something to do with SORBS, its surprising that some Primus IPs aren't working and others are.

Have you contacted Primus? Sounds like a DNS problem. Have you tried switching your DNS server on your router?

 

[hugh]

I use Google's DNS servers because they don't do redirects like Rogers and Primus.

Look for Primary and Secondary DNS server in your Router Setup.

In my router setup

Primary DNS Server: 8.8.8.8
Secondary DNS Server: 8.8.8.4

You can also use OpenDNS which I have used in the past. See Google Launches Public DNS thread

 

[hugh]

I am with Primus and I found both OpenDNS and Google to be superior so I think it might be worthwhile for you.