i know nothing about networking and all that myself, but here is what i can tell you
on the most basic level, make sure you have all the maps added to your queue ingame. if not already, then this tool should work
http://www.gamefront.com/files/15784479/Map_List_Updater_V2_0however, im assuming you arent launching from within RC, so that probably won't help you...
i searched the forums here and this is the most relevant thing i can find
http://forums.sandcrawler.net/index.php?topic=911.0i doubt this answers your issue, but i also doubt you are going to get any other reply on these forums for a while and like i said i don't really know about networking stuff. i always had someone else do the servers for me...
however, i do believe that your map list updating and all that will be specific to whatever hosting site you are using. therefore, i would highly suggest asking on that host's support forums or seeing if anyone else has done so already