[TYPO3-RTE] character classes not availiabe for cyrillic

[Burkhardt Wenzel]

there is a really strange phenomenon:

It's not possible to assign character classes for cyrillic signs.
It dosen't occur in other languages like swedish or danish which also 
have special characters.
Curiously one can assign paragraph classes for cyrillic signs.

ForceCharset = UTF-8

Any idea how to solve it?