Hi, After building boost for the iphone following these instructions http://lists.boost.org/boost-users/2008/11/42094.php , I have a problem using it in my iphone application. If I link any part of boost with the application it crashes at startup. I don't have any problem linking other C++ library. Has anybody else faced the same problem? How to reproduce it: 1. Create a objective-c class in the application (Test.h, Test.mm) 2. Include "#import " in the Test.mm file. 3. Link libboost_system-xgcc40-mt_1.37.a Thank you very much for any clue, G.