This is what I was thinking... I would go back through your references and make sure you don't have a landmine in the middle of them... This is my worst nightmare...
There was this guy that I worked with (in a lateral position, same title as mine) in a HR position, that was always NICE to me in person... but I just never felt comfortable around him... And I always felt like he was trying to sabotage me at work... (Like "accidently" shredding my faxes, etc...)
He was very adament about being one of my references, and you know, said how much he "loved me" and how great I was to work with, etc... But I just always had this feeling that he was a 'landmine' on my references, that I never would really KNOW what he would actually say to people if he was contacted... Keep in mind there wouldn't be anything negative for this person to report... but this was a type of person that could make ANYTHING negative....
I would double check your reference list... Good luck!! I know how tough it is!!