The freezing on this game is a continual issue. I try to play with my daughter and the game is bound to freeze at some point. From reading these forums it appears to be a cross-platform problem with no fix. I've gotten past it previously by unplugging the portal and plugging it in a number of times. That's getting pretty stale and I'm tired of the look on my kid's face when this ill planned software freezes.
We've had a lot of Skylander items in the past but my kid will be switching to Disney Infinity if there isn't a fix somewhere.