I just came across an issue using Superfish whereby dropdown menus were not displaying properly. In my case they were hidden beneath a flexslider block.

It turns out that this in not a superfish issue and is easily resolved at the theme level, requiring the following css for omega;

#section-header {
	z-index: 10;
	position: relative;	
}

#section-content { 
	z-index: 0;
	position: relative;
}

The fix is well documented here... http://drupal.org/node/1281696

I wonder whether this should be incorporated directly into Omega? Especially given that both Superfish and Flexslider are both popular modules for Omega based sites.