Did you fix the issue? I'm not seeing a black edge on your site, Firefox looks the same as chrome and IE. If not what OS and version of Firefox are you using? Can you post a screenshot?
Sometimes Firefox can get angry about silly things. In http://dreampix.ch/ the following two tags are missing end tags either add a </meta> or add a short end tag, />, to the end of both of these tags.
<meta name="robots" content="index, follow">
<meta name="keywords" content="hochzeitsfotografie, hochzeitsfotos, babyfotos, kinderfotos, hochzeitsfotograf, fotograf, weddingphotos, weddingphotographer, fotografo, fotografo di matrimonie, matrimonio, produktefotos, produktefotograf, schmuckfotos, hochzeitsalbum, artikelfotos, artikelfotograf, fotograf winterthur, studiofotos, fashionfotos, modelfotos, modelfotograf, tfp, kalenderfotos, kalender, sportfotos, sportfotograf, glamourfotograf, firmenfotos, eventfotograf, firmenportraits, portaitfotograf, portraits, akt, nude, stills, beatuy, fotograf schweiz, fotograf tessin, fotograf graubünden, fotograf winterthur">
http://validator.w3.org/check?uri=http% … ator%2F1.1
Mike Richards
SimpleViewer Support Team.