I found with my M3 that if I don't power up the units for as short as a 2 week period I need to call direct tv to activate. Also I find at times that I'm aiming the remote in many different locations at times to change the channel. It's pretty funny when I aim the remote in the opposite direction of the receiver and the channel finally changes. Not to often but occasionally and it gets very frustrating. The dealer claims there is no adjustment to the I.R.
otherwise we are very happy with it.