Wow, Flexor, I'm in a pretty similar situation with very similar players, more or less. I've been burned out for a while now but I've kept running things to try and get to a spot where the game could be put on hold without having to remember anything very complicated if we resume, specifically, after they're done the little rescue mission they're on.
I've been playing D&D with two of these guys for well over ten years, and I've known the rest of them mostly for a long time as well. 3 high school friends, the wife of one of them, and a guy we met about two years ago.
Ironically, the fellow with whom I've been playing the longest has the most trouble with the rules. We've been playing third edition now for a while, about three or four months after it came out, and he still assumes most spells will work the same way they did in second edition. Can't find things on his character sheet, can't remember his attack bonuses or how to figure them, etc. Same sort of thing.
Another guy is very much the "lets keep going until we get into some more combat!" Why he wants combat, I dunno, he's a fighter who calculates his every possible move to avoid attacks of opportunity, despite his excellent AC and HP.
The cleric is good, he's been playing D&D with me for a long time too, but his memory is poor and he's become very secretive -- doesn't like to let me see his character sheet or tell me what spells he's got memorized or anything like that -- he thinks I'll make sure to tailor things to render him ineffectual. He's not so good on remembering what spells do either.
The other two players I don't count, really. They miss more sessions than they attend. I'm almost entirely certain that the one guy's wife -only- plays because she thinks he expects her to do so.
I dunno what to do. Chances of one of them being the game master is about nil.. the only one who's ever done it was the first guy, and when a simple combat against some minor enemies takes over an hour and a half because the DM has to look up and re-read every monster's entry in the MM between each round because he's forgotten everything, it's not so great. Woe betide a complex combat, those were horrendous. Half the time, he had to re-read the spell descriptions for the enemy's memorized spells. The others wouldn't run anything either.
My players have also bought hardly anything.. they wouldn't even have copies of the PH if I hadn't given them to them for Christmas gifts. They bicker constantly among each other, and in fact, one player has stated he's not going to associate with one of the other players anymore, so I guess he'll be leaving the group. But who knows, he may change his mind. They both treat each other terribly for stupid, petty, vengeful reasons.
Individually, these guys are all fine.. but together playing D&D, they're bickering, complaining, irritating people who don't even pay much attention to anything that's not combat. And when they -do- pay attention, they forget it by the next day anyhow.
But if I tell them I have to take a break, they'll be upset. That first guy, the only former DM and etc, is frantic every week to play D&D, and if for some reason we can't (schedules, etc) he's morose and bitter about it for a week or so.
Well, I feel better now. I'll have to tell them I'm burnt out and can't keep DMing soon, but that'll just be a big argument.