I have found since upgrading to XCode 2.2 that if I change a header file then not all source files that refer to it are automatically rebuilt. What this means in effect is that if I change any header files I often have to clean & rebuild my entire project to avoid flakiness and crashing - especially when I change anything that is likely to effect the layout of my classes or structs in memory. I mostly work with SDL or Allegro projects, so I almost never have any .pch files or other explicit references to precompiled headers in my projects. It seems to me that the most likely culprit is the new JamTool thing that seems to be in charge of building things now. Has anybody else seen similar problems? If so have they been able to fix them?