If you go to Start Game, and want to play race maps, you have to start a ctf game and then vote on you rce maps, or you have to manually modify your mapslist.txt file (beforehand) to add the maps you want to play.
It would be good if rce maps appeared at the capture the flag maplist, or even better, option to choose which prefixes appear on each gamemod maplist when starting a new game.
-edit
the mapslist thing doesn't work