Vastly improved compatibility with older versions of IE, particularly 5.0, through the use of a kill switch that turns off all AJAX functions
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.