FYI : AMD 64bit supports version 2 of 32bit =)
" AMD64 Athlon X2 , 64bit Proccessor is compatible with amxmodx and halflife engines ( versions amxx 1.75a - amxx 1.76b" Quoted from Dennis McGowen on the computer store channel
So amd64 supports 32 bit v2 ( well atleast mine does
))