I think Dwight may not live in the consensual reality most of us accept as true. He believes in magical futuristic faxes, strange governmental conspiracies, ejecting old men from weddings into the street, and other things that normal people do not believe. This is why Jim has so much fun with him. You just have to accept this, because it is the basis of the character. He’s a weird guy, for sure, and not quite a real person, but he’s funny as hell, so it’s OK with me.
As for the Pam & Jim thing-- really, Jim is in an unfortunate position. He is committed to Karen mostly because of her continued, ill-advised commitment to him. She moved for him, after all. I had someone do that for me, and I stayed with him for several more YEARS after that even though I wanted it over, out of sheer guilt and sense of obligation. So there’s that holding him back.
But now it’s kind of Karen’s own fault if she gets hurt. She has enough information to walk away but doesn’t. After all, Jim told Karen flat-out that he was still into Pam, and in typical delusional chick fashion, Karen convinced herself, through many hours of late-night conversation (most likely her talking, him listening with feigned interest) that it’s OK that her BF is in love with someone else, it’s in the past, nothing will come of it. She’s fooling herself. Jim was probably hoping against hope that Karen would take this cue and walk away, but she didn’t, and so he’s stuck.
Jim, meanwhile, has been rejected by Pam solidly and often enough that he’s not going to be (in his perception) a dick to Karen, or give up what he definitely has, over someone who might or might not string him out again. Can you really blame him? I don’t. He doesn’t have all the information that we have about how Pam feels. They are both playing it way cool, so it’s not fair to expect either one of them to make a drastic move based on knowledge of the other’s sentiments at this point.
It’s Pam’s turn to step up and make her feelings known. The ball is in her court. I don’t blame her for not saying anything at this point, now that Jim is clearly with Karen. But she had her chances and blew them all. Now she’s stuck with Roy again. Ah well. It’s Karen who’s going to get hurt in the end, though.