Ok, I've read about setting the door locks BUT....

From page 124 of the Nav. System owner's manual:
Vehicle customization
Step1 press setup
Step2 touch Vehicle
Step3 touch Vehicle customization
Step4 touch the desired items to be set
- For a list of the setting that can be changed, refer to Owner's manual.
Step5 After changing the settings, touch "save". ...

And here is a link to that section of the Owner's manual. Note the three rightmost narrow columns. Read first page of link to see how the columns show what settings can only be done by the dealer (or ScanGuage if you play with the on-board diagnostics (OBD) toys). Look on page 525 of owner's manual for all the Door Lock vehicle settings you can change.

http://www.toyota.com/t3Portal/docum.../sec_06-02.pdf

 

There are two separate settings for locking the doors: one locks them when you shift out of park, the other at 7 mph. Both settings can be turned on, so, if you want them to lock at speed..don't forget to UNCHECK the one that causes them to lock when you shift from park. At least, this is my recall when I changed the settings the other night.

 

I think "Timing" is the critical factor with this procedure.
Where the book tells you to hold the lock, or unlock button for "about 5 seconds", it helps if you use the flashing colon on the clock display as a reference, and make sure you only hold the button down for EXACTLY five seconds. I had the same issue, till I read this suggestion on another post.