Hi,

I have a Netgear DM602 modem which is retuning refused authentication.
After almost 3 months of use, two nights ago it stopped
authenticating.
Suspecting the ISP (Tiscali) or BT etc, I tried an Alcatel USB
Speedtouch Modem, this worked first time with no problems, switching
back and forth between the two modems I got consistent results;
connection on the Alcatel and failed authentication on the Netgear.
I have been using the modem in "Router" mode.
I tried power cycling the DM602, changing/resetting the password and
user name, resetting to factory defaults, doing router software
updates (to the same version) and many combinations of the above, to
no affect.
I was running global 1.38 of the Netgear firmware; I then went to the
Netgear site to download the annex A (not Australia or German)
software
3.05NUT17 1.38, this is newer than the global 1.38 version, at least
it I think so given the extra features of the firmware, and to my joy
the modem was authenticated and I was again able to get on the
internet.
Unfortunately curiosity got the better of me and I was keen to try the
new "DHCP Spoofing" ability of the firmware when the DM602 is in modem
mode, hopefully this would get me past a problem I was having with MSN
messenger (I use a WRG614 router, to connect through to the modem) not
working with sound and high speed video etc behind a cascaded NAT,
hopefully now the UPNP ability of the WRG614 and the DM602 set to DHCP
Spoofing would solve this issue. But I am now back to square one as
the modem will not again authenticate, I have gone through the power
cycle, change firmware version (both global 1.38 and annex A 1.38),
reset loop many times in many different combinations and the DM602
refuses to authenticate in either modem or router mode, again at any
time the Alcatel Speedtouch connected first time every time I tried.
To investigate further I tried the BT test user,
bt_test@startup_domain, this works fine and is authenticated, I
believe that the password for this test user is ignored and this
points to the password part of the authentication causing problems
with the Netgear.
For anyone thinking I am not setting the password correctly for the
DM602, I checked the source HTML of the page before applying and in
the source you can see the plain text password, which is correct.
I think I have exhausted all avenues, but would appreciate other
people's thoughts and suggestions and possible solutions! (Other than
buying a new modem!)

Many Thanks
Chris