I just got my HD - I don't know what version they shipped with - but as soon as I connected to my wifi - and it registered itself - I had some odd behavior --
it was unable to download any of my books, although it could download my apps from the cloud, for example --
which made me manually sync it several times, and finally turn it all the way off.
BTW - there are no ads until you connect to wifi and reboot it.
When I started it up again, I got an "Updating Kindle - Please Wait" box, and the Amazon website has:
This update automatically downloads and installs for most Kindle Fire customers, however; you can initiate the software update from your Kindle or manually download the software update via USB.
So if your HD acts nutty out of the box, connect to wifi, sync it & turn it all the way off. It should update when restarted and behave nicely.
Just started playing with it - the screen is BRIGHT and the colors are gorgeous!