I am using CATiledlayers and UIScrollviews to draw CGPaths at different levels of detail. I am drawing big pictures (4000x4000). On the iPhone the image gets distorted for these large pictures.
I have finally found a solution. My mistake was that I set the tileSize to the size of the image I was drawing (copied from a PDF sample demo somewhere). The solution is to set the tileSize to a max of 2000x2000.
Apple confirmed this was a bug when this was posted