Superfish drop-down menu pushing content to the right

I have a problem with the superfish menu.
There are 5 categories, with only 1 having some childs. This one is pushing to the right the rest of the categories on mouse over. I tried everything with css, I thought the correct property was :
.sf-sub-indicator {
position:absolute;
display:block;
right:.75em;
top:1.05em;
width:10px;
height:10px;
text-indent:-999em;
overflow:hidden;
background:url(images/arrows-ffffff.png) no-repeat -10px -100px;
}

but nothing happens when I'm changing this...

Here is a link of the site : new.artecniko.gr