So yeah, I've been trying all week at different times. No luck. Don't really have that much time to game anymore, so I'm not going to buy the DLC "just to see if I can play with someone else". So, after a many few rounds of Solo, I'm letting it sleep for a while.
It's a shame. It is a good game (not the best) and really enjoyed it. Hope it's on GwG soon, so that the MP lights up again. Until then, it'll be a solo round every now and then.