Comment 12 for bug 226676

This is a 8.04 bug where if you have autologin enabled, then your keyboard layout settings are not activated on logon.
This has been fixed in subsequent versions of Ubuntu Linux, however there has not been a fix for 8.04.

Therefore, if you have 8.04, you can either upgrade to a newer version of Ubuntu, or configure statically your keyboard layout settings in the /etc/X11/xorg.conf file. See the Ubuntu Wiki on how to configure your keyboard layout settings in xorg.conf.