Rust on Burner

I've got a relatively new Bayou Classic banjo burner which I've used for 3-4 brews so far, and already it's starting to rust. Right now I'm seeing the spots of rust on the inside of the burner spigots, and not the outside of the burner. I'm very careful not to spill stuff onto the burner, and I've been storing it inside because I've got an old turkey fryer burner which is completely rusted, but still appears to work fine. I got the turkey fryer in a garage sale, so I just assumed that they stored it in a damp garage or something.

Am I doing something wrong? Is there a way to prevent this from happening?

(This is the burner)
http://bayouclassicdepot.com/kab4_banjo_burner.htm

Mine did the same exact thing, so I am going to guess that its just the normal course for them. I did have a couple boil overs, but running the flame for another hour would have dried that up. Mine has been rusty for about 8 or so months now with no issues