Details
Description
If you follow the steps in this forum post USING A PRE-EXISTING PARTICIPANT RECORD (sample data) - you get an error as noted. However, if you follow the same steps with a newly create participant - it works fine. It looks like there's some missing / incorrect financial transaction or financial item data in the sample set.
http://forum.civicrm.org/index.php/topic,33752.msg143150.html#msg143150