When the power runs down that far, OS X dumps the contents of the RAM onto the hard drive so that when the system loses all power, the exact state before the power loss can be loaded later (RAM is volatile and loses its information when no current is going through it)
That said, it seems that OS X can't recover properly when the boot disk is an SSD. I have the same experience that you do with my Vertex 2 SSDs. It's a problem, but one which I've learned to live with. As long as you don't let the machine go into "deep sleep" mode (either by turning it off before it sleeps itself or by plugging it in) then you'll avoid the crashes.
I wish I could help fix it, but OS X has relatively limited SSD support so odd behaviors like this are just part of the experience.