Problems with odometer MPG (Incorrect calculations)

[skymera]

Problems with odometer MPG (Incorrect calculations)

Hi

I've used Fuelly before for another car.
I've recently started to use it for my new car using the odometer setting.

So, I've filled up twice and to my calculations I should be at 45MPG or thereabouts. Yet Fuelly is saying 90+MPG.

You can see my profile here
http://www.fuelly.com/driver/skymera/micra

20th Nov I make my first fill of 14.82Litres @ 134.9/L with an odometer reading of 86,527. No MPG reading as expected.

23rd Nov I make another fill of just 7.42Litres @ 133.9/L with an odometer reading 86,676.

Which is 149miles for the 14.82L I filled up on the 20th.

So why is Fuelly calculating it to be 90+MPG?
It's as if Fuelly is calculating 149miles from 7.42Litres which is wrong.

Thanks, any help appreciated.