Hopefully now all calls to escape() are replaced with ajaxEscape() in response to Tomasz's forum post; remove deprecated version of show_category_info() from functions.php
Beginning with version 2.0.5 the language packs are no
longer included with the core distribution.
Language packs can be downloaded from the TinyMCE website:
http://tinymce.moxiecode.com/download.php
The language pack codes are based on ISO-639-1:
http://www.loc.gov/standards/iso639-2/englangn.html
Plrease try using entities if possible. Like å etc for non a-z characters.