The only reason for things to be "set back" after you change them is malware. Seems like someone is abusing a Yahoo referral code to make money off you.
Is there anyway to ban Yahoo's IP, or internet presence from my computer? Being exasperated with dwindling options and Yahoo's insistence on being the persistent friend that you don't want in your life, I am open to completely banning them from my computer.
Oh what I mean is, it's not Yahoo that's changing your settings. There's some malware there that's changing your settings, and then taking credit with Yahoo for getting a legit install. It's abusing Yahoo's bounty program for money.