Warcraft doesn't see the maps (in game?). If that's the problem (I have it,too), simply rename the map (so it's not too long and there're not much special figures like :&. etc) and, if that doesn't help, cut the map from it's folder to maps/downloads (or else, but a simple foldername)
For example, your map "TalesOfTheGrunt Beta 3.77.w3x" is in the folder "maps\download\TalesOfTheGrunt Beta3.77\TalesOfTheGrunt Beta 3.77.w3x"
Rename it for example to "GruntTales.w3x" and put it in the folder "maps\downloads\GruntTales.w3x"
(Hope the name TalesOfTheGrunt isn't too silly :? )