Freddie dug into this a bit more, and it looks like that Forum is downloading the image and saving it locally to the site.
The URL of your sig pic on Tacoma World:
Code:
https://www.tacomaworld.com/p/data/df/b6fec751/687474703a2f2f6261646765732e6675656c6c792e636f6d2f696d616765732f7369672d75732f3337303637382e706e67.png
Which looks like:
What the URL should be (from Fuelly):
Code:
http://badges.fuelly.com/images/sig-us/370678.png
So that it looks like: