XP X86-32 + Vista Ultimate X86-64 Dual boot, is it possible?

I have both VistaU 32 and 64 bit. I was running XP32 with VistaU32 dual boot for awhile until I ran into a possible virus problem so I reghosted my system which went back pre-Vista. No big.

Now I want to re-install it. Can I install VistaU64 instead of 32bit? This may be a stupid question but I haven't found any threads relating to this question. I can repartition a hard drive to allow VistaU64 its own part if need be but I'm worried that the 64bittedness boot sector will trash my 32bit boot. I don't know if the two version can coexist for dual boot. I'm not ready to give up XP by a long ways.

I will reghost prior to doing the install so if it fails no loss.

I just wanted to know if anyone had done this or if it was possible.

Thanks,

thanks I will install it this weekend then.