core_user_create_users custom fields not being set

I am able to create a user using this string.

http://xxx.com/webservice/rest/server.php?wstoken=xxx&wsfunction=core_user_create_users&moodlewsrestformat=json&users[0][username]=chuck.yocum@spatialbiz.com&users[0][password]=StrokeM!26&users[0][firstname]=Chuck&users[0][lastname]=Yocum&users[0][email]=chuck.yocum@xxx.com&users[0][customfields][0][type]=ZENDESK_ID&users[0][customfields][0][value]=181818181459&users[0][customfields][1][type]=ORG_SHORT_NAME&users[0][customfields][1][value]=SBS

My custom fields are not being set!!  Anyone see anything wrong with those last two parameters.