in unity 4.3 this problem does not exist. it appeared when using 4.5.x and was not obvious.
Scenario: i just have imagemarkers with extended tracking. in the editor and preview everything works as expected. But after buliding to ios, it looks like any movement with the camera drags the markers 3d content too much over the scene. Means, the objects should absolutly stick to where the marker is in the cameras view. But when i move the device, the objects seem to float meters above the camera image, so they don´t connect visually to it.
i tried a demo scene from vuforia, there this is not the case.
I think it is because i keep the background plane as Don´t destroy on load, and this messes it up. Maybe. perhaps. Strangly enough, this does not happen in Unity4.3.