I had a thread on a few months ago asking if anyone had similar experiences with a router not syncing with the adsl signal.
It has taken a while (admittedly because I said I was OK with being able to connect with a USB modem). A Zen Tech Support guy suggested moving to MaxADSL (I was on a legacy 2Mb fixed connection). When I moved, I totally lost sync.
Anyway, long story short ..after a "lift and shift" everything is perfect.
Thanks to Zen and the others who helped me.
Wessie