I had in the past used Microsoft browsers until I discovered Mozilla then Phoenix/Firebird. They are superior to any of the non standard crap that Microsoft produces. It is frustrating when I encounter a website that has been "optimized for Internet Explorer." This means it will do things that are not standard, hence not work in any other browser. Arrogant, very arrogant to assume we all are Microsoft sheep. I look forward to the end of Microsoft dominance so that we can get back to standards and better software. I will leave and never return most of the time I encounter one of these fancy Internet Explore only sites.
Twisted, I checked out your site with Firebird and they worked without any problems. Vortec.png was rendered properly. My only suggestion if you are interested: increase the contrast between text and background. It is hard to read on twistedweb.net. Don't give up on Mozilla.