Bookkeeping Report Duplicates
The Bookkeeping Report produces duplicates when a member renews more than one membership on a single contribution.
Looking at the code in CRM/Report/Form/Contribute/Bookkeeping.php appears to show a SQL join from contacts to contributions to memberships without relating the specific item to the specific membership. So the memberships are paid at the contribution level, and the line items/amounts can be shown at the financial item level. But without a unique join between individual membership and financial item, duplicates appear.
In this case there is also use of price sets which don't appear in the join. Possible related issue https://issues.civicrm.org/jira/browse/CRM-19936?attachmentOrder=desc
The workaround is to either a) export to Excel and dedupe the output b) create a custom query which either makes a unique join by membership_type and line item OR simply wraps the query inside a SELECT DISTINCT FROM (main query).
Please advise if there is a better solution.