"Press OK to watch TV"

Or... you might need to reprogram your U-verse remote so that it actually sends the correct commands to your TV.  Does it ever turn it off/on?

Let me add to what @baseballisback is saying...

If you have one of the remotes that has separate AT&T and TV buttons at the top there is actually a time delay between the IR signal sent to the receiver and then to the TV.  If you watch those buttons as you push the power button you will actually see the ATT button flash and then a fraction of a second later the TV button flash.  It may be short (didn't time it, but less than a second) but it is long enough that it is very easy to press the power button and move the remote away so that the TV never receives its signal to turn off.  Even though I know this I can't tell you how many times I move the remote too fast and end up leaving the TV on.   So to summarize, "keeping still" is another way of saying keep the remote pointed long enough so that both IR signals can be sent.

I'm not sure of the S20 remotes (I don't use them).  Perhaps the delay is there too but with no distinct lights it's hard to tell.

Which one do you have? @leonardb628

If you have the newer one (right). Directions to program it to the TV are on the back printed on the battery cover.

I have the remote on the right.  I did as one of the experts above said and tried to do a quick set up of the remote

and now nothing works.  Receiver will come on but doesnt control the tv.  When I push the on button, just the receiver comes on, no tv.  I did what it said on the back of the remote, but when I got to the ff button command, it never would cut the tv off.  Instead, it did something that caused the remote not to control the tv.  So, now sitting with no tv in my office, but fortunately 3 other tvs to watch.  Frustrating to say the least.  

This started because every time I turn the TV off, it wont go off, just has a screen come up that says at the bottom, "Press OK to watch TV.  The few times I could get it to cut off, when I would turn the TV back on, that screen would come up and I would have to hit "OK" to watch tv.  I shouldnt have to hit the remote twice every time I want to turn it off and on!  Never seen that before and trying to overcome that stupid problem, now no tv working at all.  thanks AT&T!!

I have the newer remote. Unfortunately, things get "out of synch" a lot and the only real fix (for me) is to keep the original device remotes nearby. If the TV comes on, but the home theater system does not, I can reach for that remote's power button and turn on the home theater sound system.

This is REAL non-intuitive and I believe @skeeterintexas agrees.

Skeeter...have you anything else to add on this subject?

I'm just glad I still have the old S10-S3. 

Heh, me too (S10-S4 but no difference)   So long as you remember there's two distinct signals sent about a half second apart (first to receiver/dvr and second to tv) it works.  I'm guessing the S20's behave the same way too even if there isn't explicit lights that blink on the remote.  Of course the problem is remembering that delay when all your interested is to turn that stupid thing off.