Resetting olpc-configured file
The Linux script /etc/rc.d/init.d/olpc-configure sets the language for X.
The first time that olpc-configure runs, the flag file /.olpc-configured does not exist, so olpc-configure get the language from CMOS RAM. It writes the language into /etc/X11/xorg.conf and /etc/sysconfig/i18n . (This may work differently in more recent releases such as 8.2.0.) It then creates (with "touch") the file /.olpc-configured . On subsequent reboots, olpc-configure will see that /.olpc-configured already exists, so it will not change xorg.conf and i18n .
If the machines were booted into Linux before the P# mfg tag was created, olpc-configure would have set xorg.conf and i18n for the US keyboard. In later boots, the P# information would be ignored because the system has already been configured.
Removing /.olpc-configured will force /etc/rc.d/init.d/olpc-configure to recreate /etc/X11/xorg.conf and /etc/sysconfig/i18n with values determined from CMOS RAM.