Problems with Ubuntu 9.10 on my Advent Netbook

I upgraded my Advent 4211c (or MSI wind u100) netbook from 8.10 to 9.04 last night which seemed to have worked fine. Then I decided to upgrade it to 9.10 and now several features have stopped working:

- The touchpad no longer works (rather important for a netbook)
- There is no sound and no option to turn it on
- The screen sometimes goes black without warning. This has only
occurred twice so far.

Some errors were reported at the end of the installation, but I took no note of them (realise now I should have done). The messages said something along the lines of "some errors were encountered, installation not done properly". Then it asked whether I wanted to report some errors and when I clicked "yes" it told me that I had no "genuine(?)" copy of Ubuntu.

Anyone got any ideas? I would be grateful for help!!! :-(

I have posted the same on the Ubuntu forums: http://ubuntuforums.org/showthread.php?t=1307922