If you want to go back to the default setting than you have to remove cablenut . Go to control panel ,than click on add & remove programs, scroll down to cablenut, then click on remove , reboot
EDIT VanBuren cablenut setting version 6 has a 3000/768 setting for cable/DSL have you try it? You can find it here
http://www.testmy.net/topic-1013