From what I've heard to keep air bubbles from forming in your mold, aside from having one of those super weird yet awesome machines that I can't remember the name of... ya gotta not stir vigorously when mixing, pour your mold in a small stream (drizzle?), and to let the rubber just fill in as it wants as you're pouring rather than direct it with movement.
And next time I'm up there I definitely wanna check it out. =) Pictures are awesome though, too.
Oh, also, just saw this in a video but tapping the sides of the mold to release air bubbles might help?