I found out, this is caused by whitespaces in the beginning/at the end of the text…
you can modify wp_term_taxonomy.description field for for affected term, remove characters like \n, \r, & nbsp ; (without spaces)??, \t etc. from the beginning and ending of the database field… (a lot faster way to fix if you have access to phpmyadmin/any other db admin tool)
of course, it would be nice, if author could fix the plugin ??