My IE8 was throwing a javascript error “jQuery invalid argument line 12″ and it looks like it’s because of the jQuery css() calls in the popeye init() method. I changing that block of code in your plugin to the below, and it seems to have fixed it. IE8 was returning “auto” for “marginLeft” and “marginTop”, while Firefox was returning “0px”. The "auto" value was causing parseInt() to return NaN which I guess is causing IE to freak out and throw an error.

I changed the relevant lines in the init() method of the plugin to the following (which seems to have fixed it so far):

var strMarginTop = obj.css(’marginTop’);
if (strMarginTop == ‘auto’) {
strMarginTop = ‘0′;
}
var strMarginLeft = obj.css(’marginLeft’);
if (strMarginLeft == ‘auto’) {
strMarginLeft = ‘0′;
}

var imTop = obj.offset().top – parseInt(strMarginTop, 10);
var imLeft = obj.offset().left – parseInt(strMarginLeft, 10);