I tried this with the latest experiemental amd64 mlton: http://www.people.fas.harvard.edu/~yzhu/hdrRc.tar.bz2 the resulting executable core dumped. This is: MLton MLTONVERSION (built Fri May 18 10:34:56 2007 on shadow) -- John Skaller <skaller at users dot sf dot net> Felix, successor to C++: http://felix.sf.net