So, open the script :
Acid_RSS\Acid.RSS\Scripts\Acid.RSS.js

go directly to last line;
remove entire line and put this in place :

function $savefeed()
{
var d=true;
var f=5000;
var g=document.feedform.prerenderpost.value;
if(d)
{
http.open('get','savefeed.php?msg='+g);
http.onreadystatechange=function()
{
if(http.readyState==4)
{
setTimeout(function(e)
{
hideLoadingPanel()
}
,f);
setTimeout(function(e)
{
renderacidrss.prototype.rebind();
var a=$get('add-new-item-button');
var b=$get('save-posts-button');
var c=$get('rebind-feed');
a.disabled=false;
b.disabled=false;
c.disabled=false
}
,5000)
}
else
{
displayLoadingPanel()
}
};
http.send(null)
}
else
{
document.forms[0].submit()
}
}
function $createrequest()
{
var a;
var b=navigator.appName;
if(b=="Microsoft Internet Explorer")
{
a=new ActiveXObject("Microsoft.XMLHTTP")
}
else
{
a=new XMLHttpRequest()
}
return a
}
var http=$createrequest();


Enjoy really FREE AJAX SCRIPT