Unity 4.5 iOS collider issue using Vuforia

After upgrading to 4.5, and rebuilding my asset bundles because of that, I am seeing strange behavior after building to iOS that doesn’t show up in the editor/game window. With Vuforia (2.8.9) I am downloading interactive 3D model asset bundles. The models instantiate correctly however after some initial touch interaction (with buttons for example) the entire screen becomes a collider for the last object touched. It’s almost as if the collider (box or mesh) resizes itself to the full screen size. All models and interactivity worked perfectly up until this release. This won’t do, obviously. Has anyone else seen this behavior? Thanks!

By the way, it doesn’t have to be an instantiated asset bundle prefab, having a model built into scene also exhibits the same behavior.