OK, It looks like a router problem after all. I have v3 of the model and there is a well documented issue with WAN side DHCP. Basically, it never gets renewed. I was on DSL before using PPPOE so never had this problem.
I am trying the latest firmware for the BEFSR41v3 that I could find in hope that the issue was resolved. Only other alrernative after that is change to a diffent router model it seems.
In any case, here is the lastest BEFSR41v3 firmware for anyone interested. It is very recent actually.