Ubuntu - natty narwhal

Around a week ago the latest release of Ubuntu - Natty Narwhal was released, the upgrade of Beth's desktop went pretty smoothly and so I decided to upgrade this laptop. Laptops are often a little more problematic and I had lots of extra stuff installed so I knew it wasn't going to go as smoothly!
But here I am now running the new release with the new Unity desktop:

This is a work in progress I've found a number of issues and as I resolve them I'll put the solutions (which worked for me!) here:

• Initially I had problems with being unable to start the upgrade with an error message about held packages - I'd been running beta versions of some applications so I needed to remove the ppa's for dontzap and kubuntu-ppa/beta before it would start. The upgrade then ran smoothly - probably around 4 hours - though I was out for some of that time so it was sitting there waiting for me to reply when I returned!
  
• On reboot I spotted the first issue - the boot menu appears to think I'm running a Xen(virtual) kernel which is selected as the default boot - if I run this the kernel soon panics! Looks similar to this bug report but that claims to have been fixed well before release. (Later: I've reported this as bug 779029)
  
• When I tried the proper non-Xen kernel it booted fine, I use the kubuntu version of the distribution but first tried logging in using the new Unity desktop. Unfortunately I was then told that the hardware was unsuitable for running Unity and it would run the Gnome interface. Puzzling as this is a fairly good spec laptop. On checking I found that the machine claims that the closed-source nvidia drivers were installed but not in use! I tried uninstalling the drivers and reinstalling which didn't help. Just by chance I looked at the package manager for the unity desktop - I was looking for a diagnostic tool and found that unity wasn't installed! I don't know if it was quietly uninstalled when it thought the hardware wasn't good enough or if it is an upgrade issue. I installed some unity packages and as you see from the screenshot Unity runs fine. I started my Linux experience with WindowMaker and so the dock looked pretty familiar to me! I recommend the help menu to navigate around the new experience there looks to lots of good information on setting up things to your choice - a sample. You'll see from my screenshot that the background repeats - I'm using twin view with the screen split across two monitors and unity can't (or I've not found out how) to persuade it to stretch the background - but then gnome had the same issue before the upgrade. (Later: the system still claims the nvidia driver is installed but not in use - however it clearly is in use!)
  
• fluxbox - my usual minimalist interface was having problems before the upgrade - I assume with the nvidia driver and this is still an issue - I get shadows on the screen and windows occasionally need a forced refresh.
  
• kde/plasma did look very nice before the upgrade but at the moment whenever I run it from login the system locks up and I have to reboot - this is before I can interact with the GUI - I've looked through the system logs and as yet have not spotted the problem. When I find a resolution - I'll update this post. Some websearching reveals this bug I don't get as far as interacting with a terminal but I have graphics effects enabled and various terms start automatically when I login - maybe some hand editing of the config files is called for?

There's some fairly hard-core geekery in the above - thanks for sticking with the description to the end!

Later - Aug 2011 two comments on the above:

• I've now solved the kde/plasma locking the system up problem, see this blog update.
• I've also discovered which of the unity background image options allows you to stretch the background across two monitors - and hugin makes the production of panoramas easy - with another blog update!