If You Fly Southwest (a little off topic)

Southwest Airlines is a great carrier. They're no-frills and in my case, they fly where I want to go. I pretty much abandoned Frontier for them. But here's an interesting little artifact of the Southwest web site:

When you try to book a flight logged into the site with your Rapid Rewards number and your password, it doesn't show you all the available flights, nor does it show you all the available fares. And the fares it's missing are, strangely, the low ones.

I discovered this yesterday trying to book from Denver to Houston. I logged in and looked up a frequent trip I'd saved and half the flights were missing, as were all the low fares. Confused, I ended up booking the trip on Frontier thinking the rates weren't available from Southwest. When my S. O. told me to check Southwest again today, I did so without logging in. All the flights and fares were there! I then tried again with my login and the saved trip - same results as yesterday. Puzzled, I took out the frequent trip and tried "straight", still logged in. Still fewer flights, although the low rates were there.

It didn't cost me much, ten dollars or so, to switch to the other carrier. It costs us a 70 mile round trip twice, though, since Frontier flies into Bush Intercontinental rather than Hobby. I'd rather have flown Southwest and will fly them in the future but I won't be logged in when I look for the flights.