I don't understand why the Obama campaign wants to make an issue of McCain's houses. In case you hadn't noticed, Obama is wealthy too. The real housing question is one McCain has no trouble answering: How many houses were bought at a discount thanks to the efforts of criminal slum-lords whose favors you returned, using your position as an elected representative?
***Update: From Byron York-
A few minutes ago, I talked to someone in the McCain camp about this. "John McCain never said he didn't know how many houses he and Mrs. McCain have," the person told me. "That is clear. He referred the questioners to his staff because this is a question that has been debated at the staff level with some reporters who, based on an inaccurate reading of Senate disclosure forms, have reported more homes than the McCains actually own, and some press reports that have indicated fewer homes than they actually own. So, by trying to avoid a debate about the holdings of the Hensley Family Trust, he simply attempted to move on to the next question."