I deliberately held-off updating the Macbook Alum's software to the latest version OS X, 10.5.6, due to the reported issues with laptops with 4 gig of RAM.Five days ago, after cloning the Mac HD onto an external drive using Superduper, I decided that it is time to try the update. I was brazen enough knowing fully well that I could easily rollback to the old software (via Superduper) in the event that I experience similar troubles.
Well, it has been almost a week and the Alum is still running flawlessly with the software update installed. For those of you who have been holding off the upgrade, below are the specs of identical 2gig RAM sticks that Apple installed in mine:
Speed: 1067 MHz
Part Number: 0x393930353432382D3030312E4230304C4600
Serial Number: 0x710E550B
If you have a new Macbook Alum 2.4 ghz with 4gig of RAM with the above specs, I believe it is safe for you to do the update and not worry about the common problems experienced by some.If you happen to be using RAM from a 3rd party, I suggest that you first clone your Mac HD, like I did using Superduper, that way, and should you experience any freezing problems, you can always revert back to your original HD state.
BTW, since the new macbooks do not come with firewire, to make a USB external drive bootable, you must first partition it using your Macbook's Disk utility prior to using that with Superduper.I partitioned mine as Mac OS Extended (Journaled).