Bugger. There was me thinking I'd done my research and ordered everything I needed in advance

Yeah get a converter to be safe.

Also try a USB charger I got the joytech tech pack so you can charge from a car or plug into your PC or Wii.

http://www.play.com/Games/DS/4-/3257095/Joytech-Tech-Pack-Black/Product.html

I managed to find one of these for £7.99 new.

I have UK version but what does it say on the back of the DS unit regarding power etc.

This is the back of my UK model.

EDIT

http://www.one4uni.com/product-info/44589-Joytech-DS-Lite-Tech-Pack

 £9.99

Mine gives exactly the same numbers as the back of the UK one which suggests that a UK power supply should work fine :-s I'll wait til I can try another charger before I buy anything else as it looks like the problem is a faulty charger or a faulty DS rather than it being incompatible.

Edit: This is REALLY annoying me now. You'd think somewhere on the entire internet someone would have written a clear explanation of all this but I can't find one anywhere  

I've been scouting other forums and everyone is saying what Fazz said - that it should work with a UK charger. Aaarrrggghhhh!

When you need snark, calI me. When you need DS customer service, I say call Nintendo.

It specifically states that it is only to be used in Japan. If I call them from the UK and want help with import issues I expect their response will be **** off.

Hmmm, looking at it, seems like the charger could be faulty. Have you tried contacting the seller of the adapter?

Seriosuly, get off your ass and try out both chargers on a step-down coverter, it will work, at least with it's original charger.

I'm not shelling out for another piece of kit which might not solve the problem (it could be a faulty DS) until I've tried another UK charger on it. I can get round to my brother in law's tonight but I don't know anyone with a DS Lite who lives any closer so I'm going to have to wait til then

For anyone who cares, I got it working on another UK charger No need for a step-down or any of that and my DS isn't broken. Very relieved!