Hm, yes, there isn't enough information yet to say whether or not the things you're observing are just coincidence.
IMHO you need to build up a record of the pattern of behaviour by noting at least the following, each time the PC fails to boot:
1. Whether or not the drive is spinning.
2. Whether or not your Maxtor drive was 'found' during POST.
You can do the latter quite easily with a DVR, which is a feature that most digital still cameras also now have.