Firefox: images don't load but work everywhere else

I had problem with one of my sites. When testing on firefox, some banners did not load. My site was sponsored so I had sponsors banners on my front page. The banners were located on the localhost i.e. <img alt="toyto logo" src="./images/sponsors/toyota.gif" />
<img alt="honda logo" src="./images/sponsors/honda.gif" />Of course everything was fine in IE, Opera an Safari.

I found that my AdBlock Plus was blocking my banners because the following default filter in AdBlock Plus /[/^a-ik-z\d=+](get|web)?_?spons?(or(ed|s))?_?(links?(auto)?)?(pots?)?(\W|_|$)(?!.*sigalert)/The solution was to rename sponsors folder on my server to something else. I choose to rename it to friends. It worked.