Strange firing problem

[rowdy]

On my way home from work this afternoon, as I approached a car in front of me I shut the throttle to slow down under engine braking, and the bike started sort of missing a little bit. It was fairly odd though, it felt as if it had knocked itself down a gear but hadn't, or as if the chain had slipped a cog a couple or three times as I approached the car, which I also don't believe to be the case as the chain still appears to be correctly tensioned and isn't worn out as it was replaced along with the sprockets about 1500 miles ago at the most.

Just wondered if anyone has experianced the same thing or might know what the problem is.

sound like its missing? bit of backfiring?
its nothing (i think) i get it sometimes

[rowdy]

Doesn't sound like its missing so much, its hard to explain really, but feels like its skipping a tooth on the sprocket (I have checked the chain tension). The revs drop for a split second and there is a small jolt.
The bike does pop about a bit when i'm slowing down due to the exhaust and fueling.

Thinking about it, it did feel and sound like it dropped down a gear on it's own (it has done this in the past), but it done it about three times, and it didn't go down any gears!
Perhaps it was just an odd case of it missfiring, but it was ok for the rest of the journey, I have been using it in the wet the past few days though.
Weather was ok on my way home too, it had only just started spitting so can rule out the wet spark plug syndrome, I have a gixxer mudguard that covers more of the tyre anyway so that should stop that from happening.