Ckeditor 4 scayt error on Enable in FF and Chrome

Browsers:

FF18: broken

Chrome: broken

IE9: works

Ckeditor Version: Latest as of yesterday

If I enable spell check automatically in my config using: config.scayt_autoStartup=true; or if I manually click the scayt dropdown and select "Enable SCAYT" I get the following error.

TypeError: ss.appendChild is not a function

http://svc.webspellchecker.net/scayt26/_base.xd.js?
Line 4107

It works fine for me on the demo site but for some reason on mine it doesn't and I get that error.

I know it's dying in webspellchecker source code itself but I assume it must be how it's interacting with the ckeditor source code or something. I debugged where it's dying and it's in an addCss function on the bolded part below

addCss:function(_3f5,_3f6){
	var t=this,ss=scayt.dynamicStyleMap[name],_3f9=_3f5+" {"+_3f6+"}",_3fa="data-cke-temp",_3fb=false;
	if(/^CKEDITOR/i.test(t.assocApp)){
		var _3fc=window.CKEDITOR.version.split(".");
		if(_3fc[0]<=3&&_3fc[1]<=4){
			_3fa="cke_temp";
		}
	}
	if(!ss){
		if(this.document.createStyleSheet){
			try{
				ss=t.document.createStyleSheet(); //Dies here and hits the catch
				ss._indicies=[];
			}
			catch(e){
				_3fb=true;
			}
		}else{
			ss=t.document.createElement("style");
			_4.attr(ss,_3fa,"2");
			ss.setAttribute("type","text/css");
			t.document.getElementsByTagName("head")[0].appendChild(ss);
			ss._indicies=[];
		}
	}
	if(_4.isIE&&!_3fb){
		ss.cssText+=_3f9;
		_4.attr(ss.owningElement,_3fa,"2");
	}else{
		if(_4.isIE&&_3fb){
			var _3fd=t.document.styleSheets[document.styleSheets.length-1];
			_3fd.cssText+="\r\n"+_3f9;
			ss={};
			ss["_indicies"]=[];
		}else{
			if(ss.sheet){
				ss.sheet.insertRule(_3f9,ss._indicies.length);
			}else{
				ss.appendChild(t.document.createTextNode(_3f9)); //Dies here which causes the error above
			}
		}
	}
	ss._indicies.push(_3f5+" "+_3f6);
	ss.scayt=true;
	return ss;
}