Comment 13 for bug 1026510

the problem here is not lxkeymap, but the fact that oem-config (ubiquity) does not offer keyboard selection during install and just defaults to whatever is set in /etc/default/keyboard (which lxkeymap just uses as well) ... to work around the issue until the bug is fixed:

edit /etc/default/keyboard to use the keymap you want
run "sudo dpkg-reconfigure console-setup", answer all questions with their defaults and reboot (along with a proper desktop keymap you now should also have the right keymap on the console)