See if this helps
I seem to recall an "invisible icons' issue. Just for giggles, hover around the bottom left of the panel to see if some edit controls appear. Just a shot in the dark.
After contacting Adobe support and going throguh several trouble shooting scenarios it ended up being an issue with my OSX 10.8.2 account on my Mac Pro. I reinstalled my OSX 10.8.2 and my Dreamweaver CS6 is working fine now.