Whenever I enter a new fuel up I don't seem to get the MPG (albeit on one entry) displayed in the Log (although it does appear in the little dashboard widget). It also doesn't seem to appear on the Facebook link that Fuelly posts up when you add a fuel up. Any ideas what I'm doing wrong?
In your case you have several fuel-ups marked as partial, which means you won't get an individual MPG calculation for that fuel-up or the following fuel-up. Here's more information about partial fuel-ups: How do I account for partial fuel-ups?
Once you have a few full fuel-ups in a row, you'll start getting a calculated MPG for fuel-ups, and they'll be posted to Facebook that way too.