* I wanted to get rid of the login sounds, and I found how to do it at http://www.webupd8.org/2010/04/what-to-do-after-fresh-ubuntu-install.html
sudo -u gdm gconftool-2 --set /desktop/gnome/sound/event_sounds --type bool false
gconftool-2 --set /desktop/gnome/sound/event_sounds --type bool false
* My wife also uses this laptop. We both want a Spanish keyboard, but she wants the menus in Spanish while I prefer them in English. For some reason, after updating to 10.04 my menus were also in Spanish. This didn't look very promising (http://ubuntuforums.org/showthread.php?t=1472193) but in the end I managed to change it.
In the language support tool I had the following languages (in that order) English (United Kingdom), Spanish, English, but then I always got the menus in Spanish. Moved away Spanish below English and all is fine now. Perhaps the support for UK English is broken?
* Sound issue solved?
In 9.10 there was apparently a bug with the sound which made many games misbehave, and the trick was to create a file with name ".alsoftrc" in your home directory (and contents "drivers = oss"). It seems that this problem is gone in 10.04, so I get rid of my .alsoftrc file and the problem does not show.
* X problems after upgrade.
The upgrade generated a new and very basic /etc/X11/xorg.conf file, so I had to regenerate my old configuration.
So far I have not found any other issues...