It does not seem to matter whether I use the complete Japanese version of WP or Eng version with plugin. When I try to input Japanese text (for example links), the text gets truncated after 8 Japanese characters.
I prefer to use Eng version with plugin for Japanese text input. I have a plugin called wp-multibyte-patch. The path is wp-content/plugins/wp-multibyte-patch.
I am using a dedicated windows 2003 server.