Hi all, this is driving me completely insane..How can I take an image, in this case a logo, make the background transparent so when I use it as a message board avatar the background matches the forum background color?

So far I have been able to make the background color transparent using the Transparent Color Selection tool, but when I save it (as a GIF), then upload it to the forum I'm trying to use it on, the white background from the original logo jpeg is still there..

I'm ready to throw my PC through my 3rd story window, LOL...