It is definitely a great mystery... but its nice to see that MMP has become a definitive home-field advantage. Nobody who watched this team in 2000 could have been comfortable w/ any game played there, but slowly and surely (and an 18 game win streak to end last season), it has become a place where you have a "comfort" level when watching a Stros game played there, knowing that you'll always have a chance to win that game. In the end, I don't think this team is going to be a "bad" road team... its just a combination of young hitters getting their feet wet, good opposing pitching, and some bad luck.
Barring injury, I don't see them ever slowing down... but, injuries do happen (and they didn't happen to them last year at all). Izzy is currently on the DL, and they subsequently lost 2 out of 3 in Atlanta. One of their #2-#3 Starting Pitchers, and an everyday player would have to go down as well for them to be truly catchable.