I don't have a suggestion but the same thing happened to me about two weeks ago. All of the sudden after my gf visited facebook, I opened up IE and it went to that weird yahoo page. I have my homepage as http:/www.yahoo.com and it said something like http:/www.m.yahoo.com. I didn't change anything or add anything and I confirmed my homepage and even looked for any new BHOs or add ons but there was nothing. I had to block the specific address to get it to go back to the original page. Weird, but true.