I have a netgearcG3000st which is constantly dropping out. Tech solution power down and power up so far 27 times in the last 12 months. Surely Optus can replace it with a more up to date reliable model under the warranty period. My virus protection tells me that it is not configured correctly, yet Optus installed it.
your /virus protection/ (which I assume runs as a program, on your computer), flags your modem as incorrectly configured??
Please tell us which virus protection app it is, so we can all avoid it.
If there isn't a restriction list on what modem you can use for your optus cable connection, I'd simply start shopping for a new modem.