The set is a November 2012 build, I've had it since December 06, 2012.
My warning wasn't meant to scare anyone off this model - I do not regret the purchase. Merely a caution about this situation I encountered, others may have different take and/or preventative measures.
After the TV warmed up the IR issue was hard to detect.
Enjoy your set; read the posts on this forum: It may behoove you to break-in your set as advised by many here - I certainly did.