I saw three small problems testing the website in Opera 12 on Mac os 10.6 :
Screenshot : http://imgur.com/a/XDhZb#0
Screenshot : http://imgur.com/a/XDhZb#1
(I don't have this problems in other browser)
I confirmed the navigation bug and fixed it. Couldn't confirm the others - seems a bit isolated. Thanks for the report though, will keep eye out.