I had this when trying some de locale: the whole of kde used an
ugly typewriter font. Then i tried some of the various iso10464,
8859-1 and 8859-15 fonts and it seemed to work.
Until the next login, after wich i saw either that ugly font or those
boxes you mentioned

But since i usually use the C locale, it doesn't really bother me.
Its just a pity that kde is this dodgy. They should fix bugs instead
of adding more bells&whistles each time...
Lets hope the new release is better (if not, i
will file a bug
report)
greetz