Hi I'm a brand new member here and i was wondering this same thing also. I've used photoshop to make a couple docks and they work just fine, but they are obviously not HD. So I tried making the dock the retina @2x size (640 X 90 from what I've read) and added @2x to the name, but when i do this and respring, it resets to original dock. So something is funky when trying to make it retina quality. can anyone tell me what I'm missing? THANKS!