O/P, two things come to mind, besides battery dying.
Dropped the fob(s) at all?
Possibile you have someone poaching codes where you park at?
*I ask specifically the second one because the one, and only one time my fob consistently got glitchy was in a certain parking lot where about two days later (after a bunch of us with the club notified P.D. we suspected it of happening) a couple of people were arrested in front of us and on the back of their car trunk was a laptop, a black box, and break-in tools. my fob has worked flawlessly since then. If someone has been poaching your signal and passing the initial one to the car/truck after recording the second the vehicle won't unlock and people think their fob is bad.
If you dropped it you may have knocked a circuit loose.
Now, as far as Code-Theft/Poaching, this has worked for me and others and may also work for you.
Check the batteries first, then do a hard pull on the buttons, holding the lock button down right next to the door for 3-5 seconds, then hold unlock for 3-5 more seconds, then do a quick succession of lock-unlock-lock-unlock a few times. Once you do the hard push lock and unlock the fobs should operate the locks quickly.
If that isn't it, have the fobs opened and see if you got dirt/grit/dried-soda/sugar/other-goop making the buttons stick and not work right.
