For other modems try the iinet Modem Help Page or consult your modem's manual. The next thing to do is try and establish whether there are actually problems with line noise. In some cases you can do this yourself as you can hear the noise when you are on the phone talking to people. The next step in line testing we would suggest is to ask Telstra to check your lines. Just because they checked out OK to your ears, does not mean they are noise free.
Modems are far more sensitive than human ears.
To do this dial 132203 and a Telstra operator should be able to test your line. Be aware however that a successful test does not mean the line is noise free. Telstra only test for voice quality and very low data quality. This is between 10 and 25 times slower than the average modem on today's desktop. Telstra has recently standardised procedures and increased operator awareness for modem related problems such as drop outs and similar Internet connectivity problems, so your Telstra operator should hopefuly be more helpful than some people have experienced in the past.