Thanks for the reply, Marisa'sMom.
It was a SPT, not a RAST; I've heard the latter tends to produce false negatives.
We switched Ben to soy milk this morning and will continue with soy milk until we're told otherwise by the allergist. I'm just not sure if this means Ben shouldn't have any dairy at all, or if cheese and yogurt in moderation is okay.
I wouldn't have expected Ben to tolerate GoodStart either, but apparently mild allergies show fewer symptoms, so perhaps he can tolerate some, but not a full diet. I'm not sure.
Anyway, yeah, I'll be discussing this with the allergist on Monday and will hopefully get some answers then, but like I said, I thought I'd inquire here in the meantime.
Thanks again!