the_headcrab

my game plas fine on multiplayer and all but if i try to load a few maps (only one i remember is impact) i get put on a team etc but after it loads the main menu just pops back up. most of the maps work but it really sucks that i cant play all of them. i have deleted the disc 2 stuff off my hdd 3 times and redownloaded and im getting the same thing so idk what else to do :\