I experienced compilation problems with Boost 1.40. I am using Visual Studio 2005 and 2008. On both Boost compiles and links fine but is unusable in other code due to compilation errors. Currently I have access to errors produced on 2008 and it would be troublesome to get errors for 2005 (but if needed I will do it) - however the are the same (as to the message): 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2039: 'long_long_type' : is not a member of 'boost' 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2065: 'long_long_type' : undeclared identifier 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(70) : error C2913: explicit specialization; 'boost::integer_traits' is not a specialization of a class template 1>d:\libraries\boost_1_40_0\boost\integer_fwd.hpp(73) : error C2913: explicit specialization; 'boost::integer_traits' is not a specialization of a class template and so on... It is hard for me to tell which header causes the error but if requested I will look for this. 1.39 was just fine in both environments. The external (non-Boost) code did not change in the mean time. Any help? Adam Badura