I have no idea what this Mr Beer setup tells you to do, but 7 days is *really* young. Even commercial breweries only turn beer out in 11 days or so, and that's with perfect conditions, huge yeast pitches, filtering, etc.
FWIW, I rack to a secondary after a week, let it go in that for a minimum of one more week, but usually two, then I keg it and it sits there for a while often. And my beer is awesome, commercial quality beer.
I think expecting good, clean beer with no secondary and only seven days is just a bit much.