Total Paid column in Event Participant Report (List) adds Fee into Total Amount

When including payment data for event participants on an event report, the Total Paid column shows numbers like "$409.10", which is Total Amount ($400) plus the Fee ($9.10). Total Paid (in that example) should be $400. The Net Amount correctly shows $390.90.

I'm running 4.6.8 and I can replicate it on the demo site: http://dmaster.demo.civicrm.org/civicrm/report/instance/39?reset=1

Screenshots attached