Hi JP Moulin,
Thanks for your question. Rand and The Back Burner already did a good job explaining some things about PA/DA so I'll stick to looking at the numbers.
I looked at the top level metrics for these four sites in Open Site Explorer:
Site PA DA # Linking Root domains # Links
www.nahoku.com 51 41 196 3695
www.mauidivers.com 53 43 228 4274
www.jared.com 59 51 283 871
www.hawaiianjewelryshop.com 60 52 325 5890
These look pretty well ordered based on these numbers to me (more links + linking domains => higher PA/DA) with the possible exception of www.jared.com which is a bit of an outlier with 283 linking root domains and only 871 links. In this case, the domain links are boosting it's PA/DA. The new model prefers metrics associated with link diversity/domain signals (linking root domains, linking C-blocks, etc) over the old one and this is what's happening with www.jared.com.