I have the Macbook Pro released one before the latest one, i.e. bought in April 2008. It is a 2.5GHz variant with 4GB of 667 Mhz DDR2 SDRAM. Is it true a 64 Bit machine? I want to run a live distro version of Linux Ubuntu on bootup, but clearly if my MBP actually is 64 Bit then I will need to download the 64 Bit version of Ubuntu for it. When did the MBPs go to 64 Bit if they currently are? Hope this makes sense.