Why Doesn't Wager Match Work On Call Of Duty : Black Ops?

ok so i got COD : Black Ops. and i earned COD $ or watever in regular free for all. then i tried to play one in a chamber on wager match and it takes like 5 minutes to load then it just puts me in a team deathmatch or a private match with people i dont no. does any1 no the answer to this problem? thxs