If you contact Yamaha UK they will let you know if your bike has had warantee work done or it if should have (I did this and they responded very quickly, just give the the VIN).

On the other hand, these bikes' fuelling isn't great and they do tend to stall in certain circumstances. E,g. when you downshift and don't blib the throttle. It's annoying, but you get used to it, just blib the throttle and don't let the revs drop completely.