Looks like you just have a bad odometer reading. Your odometer reading on August 15th was 318,298 which is quite a bit higher than the surrounding readings. If you fix that up you should be set. Here's more info about
editing a fuel-up.
It's pretty easy to spot these problems if you click the "View All Fuel-ups" link under your log book. That gives you a list of all your odometer readings.
Here's your
View All Fuel-ups view.