Hi, I just got the RM-AV3100 and immediately had the problem with my Sony receiver, but overcame thanks to this forum (to change AV modes!).

However, now I'm getting the lock-up problem, but removing the batteries doesn't seem to help - that is, I can reset the remote by removing the batteries (and retain memory), but still can not perform the function(s) needed that continually lead to the lock-up. Simply trying to delete a learned function for cable remote to reprogram, but keeps locking up even after a dozen or so tries. I also tried to do a reset of the preset settings, but the remote won't let me select it as an option. Finally attempted a compo reset of the cable option and it locks up after displaying 2 right arrows! Ugh.

I'm sure the answer may already be posted in this forum, so thanks in advance for pointing me in the right direction!