I am from australia and we have these same modems DG834GSP v3. from a company called optus.
Like many others i tried various firmware and recovery methods but ultimatley it would always tell me to contact the administrator and the firmware cant be laoded.
then i came across this:
link Firmware link upgrade for DG834GSPV3 - Netgear - DSL Hardware - Whirlpool Broadband Forums
Netgear Modem Update
that page has the firmware that can be used, i have now succesfully upgraded the netgear to V1.04.13
from 1.04.05.
So to all the software gurus out there download that file and look at the coding and i guess somewhere embedded in there is the permissions to allow the file to work.
This firmware has not fixed my sync issues, but im hoping someone out there can reverse engineer this file and make some decent firmware.
thanks.