The most likely scenario here isn't that these two have some childish feud going and refuse to be in the same room or on the ice together and are demanding trades Kobe style ("its me or him"). Most likely scenario is Miller is really tough on Petey and Petey (who is pretty quiet but really tough on himself) doesn't like that. They probably don't get along and were never really close. It's almost certainly not as big a deal as the media makes it out to be though. They pass to eachother, they make room for eachother on the PP, etc. Its likely that the media asking the exact same question over and over even after they say they'd rather move on and talk about something else is a bigger issue than anything in the locker room.
When you are losing a bunch of winnable games because of individual mistakes (Miller being the biggest culprit overall), the locker room probably isn't a fun place to be, winning solves that. Neither should be traded right now, just focus on winning games. Only adjustment related to these two is I'd like to see Miller play fewer minutes til his conditioning and play improves and I'd want to see Petey get those minutes so he can play with Hughes more. He went nearly 1.4 points per game in the time Miller was out, lean on him more and give him the opportunity til JT gets his game back consistently.