Hi Dan and welcome to the forum.
It sounds like you are picking up 2 detail records whee you only expect to find one. Also that you may be using an Append template and that the append fields are only attaching to one of the 'detail' records.
I can;t be too specific without seeing the report and the table and knowing what you are trapping on - but those two areas of concern should offer some guidance.
From the table you can use the "Find in Report" option on the edit menu to see where a field is obtained from. There is also the 'Find in Table' option from the report window. These should help tell you what is happening. Maybe also identify what needs to be fixed ... but if not give us some more detail and we should be able to find a solution for you.