I recently bought Gw2, and I've had a few problems with it, one more frustrating that the other.
So heres my main problem
When i try to launch the game, 80% of the time it just goes into black screen instead of showing the character selection. Then i have to open the task bar to shut it down and do it all over again until i get ingame.
I think i may be because of my new Gigabyte 670 GTX over-clocked edition.
Oh and by the way, this is my first post here on the forums!
I've heard people having problems with factory overclocks (I cannot understand why Anet would care about the clocks on your GPU)
So, it's possible that is part of your issue. You could try to underclock it to stock speeds and see if that helps. I know that sounds like a waste, but if that is the real cause then it might be a temporary solution until Anet figures it out from their end.
Another thing is make sure you're on 306.02 drivers, they have optimization for GW2 for 600 series cards.
hmm, that's all I can think of that's simple to examine. It could be a driver conflict if you've upgraded to 660 from something else and didn't remove all the drivers from old GPU completely (but that's a long shot)
You said you had another problem besides the black screen? what is it?