I'm facing the same issue. I've Sites installed and running with no problem but i cant see the left panel with site tree, etc. I did some html tricks and i found the buttons (site tree, content tree, etc) hidden in the top of the website (still can't see the tree).
There is what i see in IE and Chrome. I've checkd if applets are enabled and they are. I'm running 32bits JDK in Win7 64bits but early in the morning i had 64bits JDK and facing the same issue. Any hint on that?
Internet Explorer - Contributor
Chrome - Contributor