The Lomonosov 7-man Endgame Tablebase shows with, after promotion, with Rook white wins checkmates in 24. With Queen draw. I'm perplexed as well. Here's the FEN for each position. Here are the FEN positions. I can't seem to get the game result pasted here. I need to find a good pgn/fen gif creator.
Rook: 1R6/8/3N4/8/8/3k4/r7/4KN2 b - -
Queen: 1Q6/8/3N4/8/8/3k4/r7/4KN2 b - -
Link to Lomonosov 7-Man Endgame Tablebase http://tb7.chessok.com/probe