[boost] [serialization] codecvt_null.cpp not present in windows dlls

Something odd seems to be happening on the Windows platform for the serialization library, in CVS HEAD. All the text based wide-char dynamic library tests are failing as the two functions defined in codecvt_null.cpp are not found by the linkers. I've had a quick play around with the jam files but still don't understand process/library well enough to find a fix (or even casuse of the problem) -- AlisdairM