Report Builder - Part, PartBin, PartTran

I need to write a report which shows Part#, Description, LastMtlCost, OnHandQty, Calculation of LMC*OHQ, then also total stock transactions for 1998,1999,and 2000 which I use TranDate and TranQty and TranType begins "stk" from PartTran in the filters and formulas. I have been using tables: Part, PartBin, PartTran. The problem is that no matter what order I try to join the tables, as soon as PartTran and PartBin are both joined, it distorts my OnHandQty total. I've tried grouping by the Part# in Part and in PartBin depending on the join sequence. I've created hundreds of Report Builder reports so I am familiar with it. Hopefully I'm just overlooking something. If you can offer any help at all, please e-mail or call 219-264-2190.
Thanks in advance!! Ann Harrell

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