Beware of Caching

I recently found that doing a "Clean All" in Xcode is not enough to make a clean build.  I removed an image from the project thinking it wasn't needed.  I did a "Clean All", rebuilt, and everything looked fine in the simulator.  I installed a fresh build on the device, and saw that an image was missing.  I went back to Xcode, did another "Clean All" rebuilt, and it still looked fine in the simulator.  I then deleted the app from the simulator, exited the simulator and rebuilt.  Only after all that did I see the missing image in the simulator.