To the OP, yes you can lower the floor. I have never lowered one, but
I have raised them. However, be warned. You will get plaster cracks,
doors and windows may not fit and will get stuck or not shut properly.
The more you move the house, the worse these problems will be.
If you do it, turn each post 1/2 turn per day. Dont do it all at
once.

Hmm...the person that replaced the beam replaced it, *then* replaced the
windows and some of the doors. The master bedroom door is already off
kilter, I had to sand 1/4" off of the end just to get it to close. Also,
it's not off at the ends of the house, just the center 3 or 4 supports are
too high, so I might get lucky and not effect the windows. The exterior
walls are all supported by the cement foundation for the basement.
Hmm...I'll have to give it some thought. It bugs me, but cracks in the walls
etc. also bug me :-). I might try to drop it a half inch and see what
happens.