To check for duplicates you may create a filter to show duplicate rows based on Date and Activity. In creating filters, the advanced tab allows you select duplicate rows only.
Once you have duplicate rows, you can use the "Find in Report" feature and see whether it is coming from your report. Highlight row you want to check and click "Find in Report" button on the ribbon. If it is coming from your report you can now fine-tune your traps to exclude the duplicate rows.
If trapping can't solve the duplicate rows, you can remove duplicate rows by creating a filter as well.
Hope this helps.