Doug, in the current OSL2-V2 results, many of xpressive tests fail at runtime with some dynamic linking error: http://tinyurl.com/q62ly The error basically says that 3.4.4 binary links to runtime from another gcc version. I have no idea why it shows up on one test, but I'd need your help to solve this. Can you do this: 1. Given me the exact content of toolset files you use for V1 (not V2) testing. 2. Give me the content of user-config.jam 3. Go to libs/xpressive/test, touch c_traits.cpp and then run the "c_traits" test using -n option with both V1 and V2 and with both compiler version. I think that the following commands should work bjam -n -sTOOLS=gcc-3.3.6-linux c_traits bjam -n -sTOOLS=gcc-3.4.4-linux c_traits bjam -n --v2 gcc-3.3.6 c_traits bjam -n --v2 gcc-3.4.4 c_traits and send me the output. Thanks in advance, Volodya