your not the only one mate...mines gone too.........i noticed a strong smell of exhaust fumes in the header tank the other day and a bit of brown foam on top of the water but no water in the oil at all. Its not over heating or loosing loads of water so i think its on its 1st stages of going but it got worse after giving it a shit load of abuse at my local meet ....oh well,shit happens.......at least it will give me a chance to look for my oil leak