If you copy and past entries from Word into the OUWiki, you get an error:

Database problem: Data too long for column 'xhtml' at row 1 (code OUWIKI-E:\Websites\...oursite...\root\moodle183\mod\ouwiki\ouwiki.php/1614)

It appears to be generated because of the additional markup from Word text, as the actual entries are not excessively long. The workaround we are currently using is to ask students to use the Word Cleanup button or use text mode for editing, but this seems beyond the capability of some of our students.