Game crashes seemingly after certain amount of play time

I've been looking through the search results for "crash" and so far have found nothing describing what I am expieriencing.  Basically, the game seems to be on a timer but not like a memory leak.  If I start a new character things seem to go great and then about ten minutes into the game, things crash.  Going on that description you'd think the game was just crashing every ten minutes but that's not what I mean; if I start a new character, play for five minutes, then save and go back to that save, the crash will happen five minutes later instead of ten.  If I play that save for three more minutes, save again, and come back to it later the game will crash in two minutes.  It's how much game time the save has logged that seems to matter, not how long I have been playing for that particular session.

It doesn't seem to matter where I go or what I do, though I haven't been outside the Bitter Coast region yet.  I am running Morroblivion with all of the replacers recommended in the installation guide including Eloth's overhaul.  I should also note that this does not happen to me when I'm not running Morroblivion's plugins.