it might have something to do with the SSD, intel SSD =Nice. Not sure what controller the intel SSD uses, a firmware update might be available? I know some sandforce controlled SSD's had a firmware bug recently.
so prob. not the SSD's fault, maybe the way OSX is handling sleep and hibernate modes now with an SSD?.......it's just the one of a short list of things i can think of.......... I have seen a few postings on the web about people complaining with a similar OSX+SSD issue. Check and see if you have any zombie processes? check " Console" logs as well which helped me with a recent problem.
You may also check to see if your RAM is " ok " you mentioned it was upgraded to 8GB......... do an extensive test on your RAM which will take a long time. Bad RAM can do wacky things and work fine until you do something specific or push the system hard.... i had a windows system years ago that would only crash if i played a game. One bad RAM module.
It's been over a week since you asked the question, and while i don't have any experience about this specific problem thought i would make a few wild guesses even thou you may have thought of these already.