Guilt by participation: New McCain ad

Ok, folks, comment away:

I maintain that the connection to Ayers matters but more from the perspective of what it means for Obama’s education policy and economic policies now. For instance, I would like to know if Obama would appoint someone with Ayers’ ideas about education. I do not dismiss the judgment problems inherent in maintaining the relationships he did but I am also concerned about who he would appoint to various positions in his administration. Presidents often look to long time advisors and mentors. It seems reasonable to examine those who have helped and mentored him along the way.

One day Obama didn't know about Ayers, the next day he thought Ayers was rehabilitated

For days, the Obama campaign said he didn’t know of Ayers’ terrorist past when he attended the political event on his behalf hosted by Ayers, today (actually tomorrow) he says he thought he was rehabilitated.
Which was it?