Imported categories duplicated and broken partially with non-ASCII characters.
Category duplicated as original one and broken one. Broken one's broken part is non-ASCII characters which are presented in URL-escaped form.
I think this is duplicated URL-escape function call problem.
The data XML is exported in older version of WP(about 2.8.4), I cannot know it's version exactly because it displays 'Get Version 2.8.4' at place of version text instead of it's version.