I've switched recently to an UK keyboard, from a FR keyboard. It is an usb keyboard, and first I plugged it in, I had to launch dpkg-reconfigure keyboard-configuration in order to request the correct layout (ie: uk).

But after every reboot of the machine, the laytout comes back to the FR layout. How can I make the modification persisting?

I am using Ubuntu, running the Stump Window Manager. And here is the /etc/default/keyboard at any time (that is right after startup, and before and after I run the dpkg-reconfigure tool)

XKBMODEL="hhk"
XKBLAYOUT="gb"
XKBVARIANT=""
XKBOPTIONS="terminate:ctrl_alt_bksp"