Early on in the campaign, the biggest problem was getting the PCs to work together - and it was partially my fault. I gave all of the PCs secret missions/motivations, some of which were conflicting. Having gotten used to dealing with people who had gamed a lot together in the past, I assumed that they would figure out ways to weave those into a coherent set of goals as their PCs evolved and changed.
Some of my PCs took to the RP/Backsory elements like fish to water, while others stumbled and grew frustrated that they weren't recieving enough of the story's spotlight. Yet, when the spotlight swung their way, they didn't want any part of it, complaining that the game was slowing down, and that they were bored because they weren't killing anything!
What it all came down to, of course, is that this new group had a widely varying style of play preference. 14 months (or so) into the campaign, that issue has pretty much worked itself out, with people compromising to reach a balance of enjoyment for most, if not all.
On top of all of the Out of Character issues, the secret missions and goals that I had created to flesh out the world nearly killed the campaign! Whole sessions would grind to a halt as the players all tried to advance their secret portfolios, all while trying to maintain the secrets both in- and out-of-character. No one could help anybody else because no one knew what the others wanted/needed.
That's started to work itself out, as well (Thank God!). Now 15th level, they've finally started to share the important stuff (some of which, when put together, reveal necessary clues about the campaign that have been ignored for months), although a few people stubbornly hold on to their secrets, for reasons I have yet to fathom - I've had to offer bonus XP to encourage people to metagame!
All in all, it's made for a fantastic story in-character, even as it has made for some tough interpersonal moments, out of character. In previous groups, the problem has always been to encourage people to take the game a little more seriously. In this one, it's been to remind them to back off a bit, and put the game in perspective.
Sometimes, I think I as the DM/GM forget that not everyone can take a deep breath, step back, and remind themselves that it's just a game and not worth losing or bruising friendships over.
And THAT'S what I find most frustrating.
Note: Since this is a thread for complaining, that's what I've done. But I do want to say that I love my players like family. They're a great group, and a tremendous bunch of friends to have. They really helped make Northern Virginia feel like home when we moved out here from the midwest, and I'd probably be insane if it weren't for all of them.
