If you complete an order in Altru that has multiple items of the same cost, such as multiple tickets for multiple dates, multiple merchandise items, or multiple memberships of the same cost, only one of those items shows on the Total Revenue and Payments Report. For example, if the order was for $80 total, but there were two tickets for $40, the Total Revenue Report only shows $40. If you mark the box to include payment method distribution, you will see the payment method distribution amount is correct while the order amount is not.
This was resolved in Altru version 3.19. All sites were updated by November 2014.