Thanks to Noel Belcourt, the trunk Sandia-gcc tests show results side-by-side for gcc 4.4.1 without and with C++0x features enabled. See http://beta.boost.org/development/tests/trunk/developer/summary.html Several Boost libraries are passing without 4.4.1 C++0x features but failing with them: http://beta.boost.org/development/tests/trunk/developer/assign.html http://beta.boost.org/development/tests/trunk/developer/config.html http://beta.boost.org/development/tests/trunk/developer/dynamic_bitset.html http://beta.boost.org/development/tests/trunk/developer/functional-forward.h... http://beta.boost.org/development/tests/trunk/developer/fusion.html http://beta.boost.org/development/tests/trunk/developer/interprocess.html http://beta.boost.org/development/tests/trunk/developer/intrusive.html http://beta.boost.org/development/tests/trunk/developer/mpl.html http://beta.boost.org/development/tests/trunk/developer/parameter.html http://beta.boost.org/development/tests/trunk/developer/rational.html http://beta.boost.org/development/tests/trunk/developer/spirit.html http://beta.boost.org/development/tests/trunk/developer/xpressive.html It might be helpful if Boosters take a look at these failures, and report their conclusions. If the problem is a bug in gcc, please indicate if the bug has been reported to the gcc folks. Thanks, --Beman