Aye, I put about 77 litres in after getting a friend to turn up with fuel. The gauge was reading just above the empty mark (I was on my way back from picking the other half up and heading to a fuel station), the thing definitely ran out of fuel.
So I'm guessing the mechanical fuel gauge thing in the tank might be getting stuck? That's the only thing I can think of.
Edit: I should mention I'm in no way complaining about the consumption because if it does 8MPG I can deal with it, I'm not daft enough to think adding more power to the car would increase the MPG it's getting.