PPPoA failure

Some years ago I arranged a Zen account for a friend, and supplied a Sweex
CC300011 router. The connection appeared to work reliably. The exchange is
very near (a few hundred yards), and the line download rate is over
7Mbits/sec with a good SNR margin.

My friend decided she would boost her income by re-selling Utility
Warehouse. She therefore felt obliged to buy her internet connection from
UW. Soon after she complained that her internet connection had failed. I
investigated; the router reported ADSL sync but no PPP connection.
Rebooting the router corrected the situation. After several similar
failures I concluded that the router was faulty, and replaced it with an
Edimax AR-7084A router. I monitored the connection and it continued to fail
several times a day, sometimes for much more than the couple of minutes
required for re-negotiation. The situation was muddied by a problem with
water leaking onto the BT master socket which was finally resolved by
relocating the master socket.

Later, she wanted wireless, so I swapped the router for an Edimax AR-7084GA.
The unreliable connection persisted, with similar symptoms - breaks
occurring up to a dozen times a day, sometimes lasting several hours. On
every occasion that the router status was examined, it showed ADSL sync but
no PPP connection. This router does log failures rather cryptically, and
experience shows that username/password errors are reported with CHAP
failures. This router doesn't show such errors; and indeed when rebooted or
when the phone line is unplugged and reconnected the connection is
re-established.

Both the Sweex and non-wireless Edimax routers continue to work elsewhere
for users who do not use Utility Warehouse.

The UW technical support people suggest that the Edimax routers are
incompatible with their service and recommend Netgear. I can understand
that they might recommend a router that they are familiar with, but is there
any possibility that their service might be incompatible with other brands
of router?

--
Graham J