I found this thread after my Envy, which I bought two days has crashed 12 times since in sleep mode.
I have exact same errors on my dmp files as listed here. I called HP support as a customer and unfortunately they don't know SQUAT!!
He said, it's either a motherboard hardware problem or an OS Win 8 corruption issue, the only way he can tell is to go in to my PC and restore to factory settings to determine which is the case.
I declined, will return PC to store tomorrow, if I have to start fresh and reinstall all my programs, data and files that I spent the last two days adding to this PC, I would rather just get a new one.
He had no idea of this problem's existence and has not heard of it before, so word has not reached HP thus far.
I informed him that he needs to let his superiors know that this is a major F'up on their end and I am not the only one with this issue, he said he would, riiiiight.
Disappointing, it was a nice computer other wise.