We launched a new version of Fuelly Mobile in February
. The new site is based on jQuery Mobile
which updates frequently. So it's possible some changes are happening the background that aren't working out for your particular phone/browser combo. With that in mind we created a "Basic" version of the site that sidesteps jQuery Mobile completely, so you might give that a shot.
Go to Fuelly Mobile and look for the "Basic" link at the bottom of the page. Click that, then the "Home" link on the following page and you should see an extremely basic version of Fuelly Mobile. See if that gives you better results.