CoD: World at War online problem Ps3

Hello everyone !
I have a major problem with my CoD game for my Ps3 !
I can log on the online game with no problem, but, when I want to join
a game, it doesn't want to start ? It says: trying to join potential matches, but,
it keeps saying that, and I can't get in a game ?

- Could it be a network configuration error ?
Or because I'm from DK ?