FYI, it seems now that the RenderTransform property of objects is by default a MatrixTransform (identity matrix), whereas in Beta1 it was null until you assigned it. So if you were testing for null in Beta1 it may cause you problems. I found now that I needed to change my test to object.RenderTransform.GetType() == typeof(MatrixTransform). Of course this won't work if you're actually using MatrixTransforms...I suppose in that case you may need to test the IsIdentity property on the matrix.
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