I did a clean install of 13.04 about a month ago and all is OK - I do the updates when the update windows pops up. (This is a new machine and for some reason 12.04/12.10 did not like the graphics (on board intel chipset)). I was under pressure from my wife to 'get her pc back' so tried 13.04 - it went like a dream and although I knew it was not official it has run like a dream. (Mainly used for email/surfing/libreoffice). Pic1 shows indeed that it is 13.04 - however, today a System Reporting window popped up and indicated that this is a 12.10 machine - see pic 2. I put this down to 13.04 no yet being official - I take it that this is not an issue.