i'm going to keep mine @ 40* with s 3* differential. remember the beer won't o through those types of temp swings, just the air. I like to keep mine a bit colder then most. That way if it needs to be warmer i can just drink it slower.
I'll also be using a small computer fan in mine to circulate the air, for more accurate/stable temp.
How are you powering the computer fan? Can you get some that plug directly into the wall without wiring something special up? Where do you put the fans in the keezer? Also how tight do the faucets need to be to the shank? I tightened them with the special wrench but the shank kept slipping in my hand. They are pretty tight but I bet I could really reef on them more with a vice or pliers.