The RR DNS redirect opt-in/out is tracked by modem MAC, so if you swap modems, you have to opt-out again. Once that is done you may have to wait a few minutes and reset your modem or refresh your IP lease. The main opt-out setting didn't take instantaneously from what I remember.
The settings on the preferences page, have previously been tracked by cookies so if you toss the cookies they appear to reset to defaults when you log-in again. but they don't actually change any TWC settings unless you hit save on the page.
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www.dnsrsearch.com/prefs.phpTWC, Charter, and Earthlink DNS redirects used the same system/provider if I remember right when I had them and had to configure them. I haven't messed with these things in years, so it may have changed, especially if they changed redirect providers.