WIERD power loss on the way to work this morning...

okay, so I'm on my way to work, cruising along at 65 on the freeway, then all the sudden my engine gets weak. well ... not really all the sudden, it was a steady, noticeable decrease in power over the course of about 15 seconds or so... to compensate i give it some more foot, and it starts misfiring like crazy. i back off a bit, and then it smooths out except for an occasional misfire (out of the ordinary for this engine, it never misfires), with only enough throttle input to maintain speed at 50-60 mph. i get to work, pull into my parking space, and rev the engine a few times. normally, this motor purrs, i mean it's really smooth all the time. now it sounds like it's running short a cylinder.

i throw the hood up and check the manifolds, and it *seems* like everything's firing.

thoughts?

last night, i took it out to gas up so i wouldn't have to do it this morning. I topped off the oil bath a week or so ago and thought that i might have overfilled it (and gotten some oil in the carb), so i dunked some fuel system cleaner in the tank. it said on the bottle it would treat *up to* 21 gallons, and to empty the contents of the bottle into the gas tank (without giving any warning about maintaning the ratio of one bottle to 21 gallons). I emptied the bottle into the tank before filling up with gas, so it should have been pretty well mixed. as i was topping off, a very charming little rotund Hindi lady came up to me and managed to pantomime that her car wasn't starting. I left the Jeep idling for about 15 minutes while we jumpstarted her car, then drove the Jeep to my flat about 3/4 mile away. now, the Jeep was running flawlessly from the time i started it up this morning to about 7 miles down the freeway from my apartment.

here are my theories and questions:

if it was the fuel system cleaner itself, it should have made it to my carb *much* before then, right? is it possible that this problem is because of an overconcentration of the cleaner? is it likely/possible that it wasn't mixed well enough and the engine got a shot of *mostly* FS cleaner? could something substantial have simply broken loose and clogged somewhere in the fuel line, or is this more likely a mechanical failure of some kind?