Game broken after Unity 4.5.1 update

Hi

Everything with my game was ALL GOOD until I updated to 4.5.1 and now my zombies are all jacked up. Like one or two will chase me how they suppose to..a couple will chase me BUT get short legs that move really fast for some reason...and other zombies just jump to the skin weight pose! I'm sooooo lost sorry if i'm not explaining it clearly it's just so random and confusing became all the zombies share the same model and run animation so I can't understand why 3 different things are happening.

I've attached a picture to try and help explain the situation. The only error I've ever gotten was a Input rotation is {Nan,Nan,Nan,Nan} which goes away if I close the scene view. I learned that for another users forum who said that it is a bug within unity

Any help would be greatly appreciated Thanks,

UPDATE: My game is working again! :) I ended up having to change my zombies running animations(from within the animator view) from a Blend Tree to a standard animation. Not sure why but HEY i'm just happy it's back up and running. :)