Mixed multiple architecture Debian installation

[L V Gandhi]

I have a PC with core2 duo E4500 processor which shows by Intel processor
identification utility as 64 bit architecture. I have Windows XP and Debian
squeeze 32 bit installed with dual boot started by Debian grub.
Can I install ia64 version as triple booting and boot with grub of ia64
version in MBR?
What are the problems with multiple architecture installation?
-- 
L V Gandhi