I'm currently running Ubuntu 12.04 LTS 64-bit on a Macbook Pro 5.5. I'm dealing with a couple of issues with the backlight and other little pesky things which with my understanding could be caused by the silly Mac, or just a brand new LTS, or both. Is it known for macs running ubuntu to run better with the 64-bit or 32-bit? I know that the bit size deals with info transfer, but I'm just curious if the versions react differently with the macs cpu and hardware (for example if I switch to 32-bit would the backlight issue be resolved) and resulting in a better user experience.
=) thanks in advance
Using a 64 bit kernel for a 64 bit capable processor will guarantee that the kernel will be using optimizations for your processor. Not "legacy" or compatibility features for older processor architectures.
Using a 32 bit kernel will not help with any of your issues and I would say that its extremely uncommon to have problems because of using 64 bit kernels instead of 32 bit ones.
You are having backlight issues but I cant tell what hardware you are using. According to google, its Nvidia, if so try switching from the Nouveau driver to the Nvidia driver which can be done easily in the "additional drivers" program.
If this doesn't help try installing:
mpb nvidia backlight driver
for your nvidia card.
If you have more than 3gb ram , better go with 64-bit. As your processor is already capable of running 64 bit programs.It will provide you little edge over processing.