Weird noise on css hover

Question

I figured I would ask you all before emailing the developer. Is anyone familiar with a strange 'noise' accross the screen on a CSS hover? This only happens when I use a variable instead of a number in the cssMap function as seen below. I am using Winston Wolf's CSS Clickable Map . See in action here: http://animalnecessity.com/company/where-to-buy

var windowWidth=J(window).width();
            console.log(windowWidth);

            if (windowWidth>500 && windowWidth<750){
                var size= 750;
            }
            else if (windowWidth>750 && windowWidth<960){
                var size= 850;
            }
            else if (windowWidth>960){
                var size= 960;
            }
            else
                console.log('Not working');


            J(function(J)   
            {       
                J('#map-usa').cssMap(       
            {           
                'size' : size,          
                'tooltips' : 'floating',            
                'cities': false,                    
            });     
            }); 

Answer 1

Your continents image seems to be corrupted: http://animalnecessity.com/skin/frontend/default/animalnecessity/cssmap-continents/continents-960.png

And here it is in Chrome: