This could be one of the dumbest questions I've ever asked, but...
It shouldn't take hours and hours to add and switch kde language settings in
System Settings -> Regional & Languages -> Locale -> Add Language
should it? I had to cancel and then restore .kde from backup to get things working again.
Remember to backup .kde if you're going to try this.
If this behavior is confirmed, then I will file a bug report
Thanks
Eli