Updated binaries. https://bitbucket.org/goshawk/gdc/downloads/gcc-4.6.1-tdm-1-gdc-7e22befef29c-20111210.7z * GDC now targets i686 processors. Was targeting i386 which required substituting functions for atomic instructions. I will release MinGW64 binaries soon then work on updating to tip and changing the default compiler to D2. -Daniel