Also, when the game is searching for an opponent (so, just before the game starts, the match-up phase, so to say) there is a notification somewhat around the lines of 'this username already has a PvP game open' (paraphrase).
ALSO, more than one player (that is, me and one other player at least) get the opponent called NaN.
All in the hope these pieces of information help fixing PvP1 soon.
Go team! 8)