BMorley- -
I'm sorry, I can't really offer anything to help, but I just wanted to say I had increased pain issues when I quit smoking, and sometimes it just takes the body a longer while for it to get used to living w/o the nicotene, and all of those chemicals. I know it definitely did in my case.
Did he not use any nicotene replacement aids? I wonder if that would've helped?
You could try posting the same message on the sinus & allergy board...I believe there is one here?

Best of luck to your dad, I hope he quits again. (And how nice of you to help him!)

Deda