I think this might be it (can't reach the DNS servers). I swapped the 3.1 modem for a 3.0 modem I had used for a long time with no problems. So far the problem has ceased. I was actually hoping it would be the modem, but the behavior from pfSense is well uhm, a bug if you ask me. You're trying to work out a problem and pfSense just contributes to the problem.
Well thanks all for replies.
Yes, I could ping. Yes it was a rapid reply. I did not ssh into the box. Once the above appeared to solve the problem I did not want to go back to the old modem since it seems clear (for now) the problem is not with pf Sense.
Regards,
Barry