Amarillo to Tampa - Weird TSA Pre Twist

My annual January trip to AMA is over.  I've flown out of there many times since 9/11.  Why is TSA so weird there?  I won't go through all the strange things I've had to do to get through security there, but this time my boarding pass said "Pre" and as I approached security I got the three beeps and a plastic card with TSA logo on it.  OK, I suppose.

So I get to the machines and take the cell phone out and walk through.  Then I hear "bag check!" and wonder what the heck.

So they look at the liquids, etc an re scan the bag.

I asked the agent about this.  I said I thought Pre meant the liquids were ok.

To which I was told, "Here at Amarillo the passenger is eligible for Pre but not the bags."

HUH?

I guess this simply means that you can keep your shoes on and that's about it.

http://flightaware.com/live/flight/SWA613/history/20140117/2135Z/KAMA/KDEN

http://flightaware.com/live/flight/SWA1964/history/20140118/0001Z/KDEN/KTPA