Thanks, the link helped indirectly... I already had looked at the Hosts file but had not noticed that it had been written to by an old program I used in the past for my Dialup connection, TweakDUN.
After editing out all entries except:
127.0.0.1 localhost
And renewing the IP address using the ipconfig /renew command, I got it to work.
Interestingly both of my machines (XP Pro and Win 98) could not access those two pages so that was the tip off that it was something in common with both machines.
Still I am not sure why those two particular sites were not working. There were many other sites listed in the TweakDUN Hosts file that worked before and after the edit.
BTW I did upgrade and scan with Ad-aware 6. Glad to see that they seem to be back after a while without updates.