Be sure your flight is booked into F, A or P. Doesn't matter what column it is, if it's booked into one of those buckets you're fine.

You might be getting some PHX-LAX/SFO-JFK flights booking into business for the transcon sector, and you don't want that. In addition, I just did some dummy searches on usairways.com and found some of these "business" flights, but as soon as you click it comes up and says "Business class not available. You will be seated in First Class." Seems good to me.