Windows 2000 MUI doesn't change logon screen language

>From past MUI deployments, I know that when I log on as a local admin
and want to change the MUI language, I am asked whether I want to set
this language as the system default. I click yes, and all user accounts
_and the logon screen_ change to that specified language.

Now when I do this on a fully patched Windows 2000 machine, it does
change all the users, but does not seem to change the value in
"HKEY_USERS\.DEFAULT", which is necessary for the logon screen to
appear in that language. When I manually change that value to the
desired language and reboot, everything works as expected. But the
control panel applet ("intl.cpl") doesn't change it.

Any information on this issue or possible explanations/workarounds?

Thanks, Claude