Thanks for the replies. I guessed as much but thought I'd ask as it would be good if I can save it, the 2700HGV is by far the best router I've had on my long line ADSL. I'll do some more work on it before it goes for recycling, I'm still on the hunt for the elusive 'debug' mode.
Luckily I bought 2 spares and am using the 2700HGV I flashed with QWEST firmware, can't say I've noticed any difference in the WiFi power and some devices stop talking to it after a couple of days so I'll have to use my other spare before too long.
The odd thing is that next door has 2 ADSL lines, both went off at the same time yesterday but both survived. I know the setup well as I've helped configure them, one is a BT HH6 and the other a cheap entry level Plusnet. Our lines come from the same pole and all 3 have the new ADSL faceplate.