I was there and I genuinely don't recall hearing any booing. A frustrated sigh at full time maybe, but that's it.
Also, I'm in Club Wembley and the two seats either side of me have been empty for both games. And the only other person who seems to shout/sing is a 14/15 year old lad behind me. Everyone else very much seem like tourists. I would say that I regret buying in CW and wish I was with other more vocal fans, but now I just see it as my mission to be the noise for my section.
It's going to be a long season at Wembley.
Interesting that there are conflicting reports from people who were at the ground. As I said before, I watched on TV and heard nothing. If people who where there have differing accounts, it probably wasn't that loud.