Occasionally though boot never gets parts step 2.
What - if any - message is on the screen when left in the "limbo" state?
I have noticed that it is not uncommon for hard disks not to spin up fast enough to report present when the boot sequence looks for the boot disk, in which case a "non-system disk or disk error" message usually appears.
This usually happens when more than one disk is present on an IDE channel. As I've not used SATA much I haven't experienced that problem with it - yet.
It could be a power problem, in which case I'd expect SATA to behave similarly to PATA.
SD