Chain or gearbox problem?

[Schmeeky]

Over the last few ride outs, a problem has started with my gears - it jumps out of 5th into 4th occasionally when the throttle is rolled off a little, and yesterday it jumped out of 5th into neutral, which was disconcerting to say the least...

I was talking to a bandit owner at the vintage bike meet yesterday, who thought it might be because the chain is slack, but I've had a look and the amount of play seems to be well within tolerances. I know Suzuki gearboxes are pretty strong, but am worried that it might be on its way out, which is very worrying as I can't afford a big repair bill at the moment, and I can't ride a bike that's potentially unsafe...

Basically, I'm asking if anyone has any knowledge of why this happens, and any ideas/solutions...

Bike's a Bandit 1200, btw.

[dern]

You could have the chain off to ensure that there aren't any severe tight spots but I can't imagine any situation where that would cause the gearbox to drop in to neutral or to go from 5th to 4th. I assume you've thought of this but are you absolutely sure you're not catching the selector with your boot?

[Schmeeky]

It's definately not catching the selector with my foot - as it always happens in 5th gear I'm therefor in 'swift cruise' mode, with the balls of my feet on the pegs, not close to the selector. Which means it's something else, and the chain seems to be ok....

I'll go and talk to the lads in my bike shop tomorrow - from posting here I was just hoping some kind soul would say something like "Ah yes, it's the upper dog locator, give it a quarter turn clockwise and it'll be fine..."