(Forgot to answer one of tashi's questions)
Yes, I do have "Resident SDHelper" enabled, and have for at least two weeks now (not positive it was before my last post), set to block pages silently. Just to see it work, I set it to "popup" or whatever, and was often interrupted by "do you want to block" messages. Satisfied it was working, I set it back to "silently."
I did not have "Resident TeaTimer" enabled; I'd never gone into Advanced mode before. Just now, I went into Advanced and enabled TeaTimer, and will hope that helps.
Again, tashi, thanks for your help! I appreciate in advance any additional help anyone can give me! I'm not even sure if "advertising.com" was even the source of all my problems; my internet protection software classifies most of the visited websites as "R-rated" in some form or other...Once again, head scratcher!
Thanks,
dlw