So one issue with the 64bit version and the latest "numpty" is that the issue with the astrometry script and the rule changes in numpty about dynamic casting:
TypeError: Cannot cast ufunc add output from dtype('int32') to dtype('uint16') with casting rule 'same_kind'
It appears that according to that comment that the change was reverted.. so perhaps a python/numpty update will sort it out. It looks like ".astype()" needs using in the script.