That is correct. IR, will always fade. It takes hours to days to actually cause burn-in.

You've had this set since September? Approx how many operational hours do you have on the panel? Generally after 200 hours the amount of image retention lessens.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris