Boost on AIX 5.1 with xLC 6

Has anyone been able to compile a recent version of Boost on AIX? I keep getting a compile error in the is_enum.hpp file. Something about "non-type template parameter of type bool". Failing that, what is the last known version to successfully compile on AIX? If anyone is interested in figuring it out, I can include a log of the failed compilation. I'm quite willing to test any ideas in order to help get Boost compiling on AIX. Regards, Dieter