Duplicate lines in Crystal Reports

I'm a newbie to Vantage and to Crystal Reports, and to this eGroup, so
please be gentle...

I'm creating some wonderful reports in CR ver 7.0.100.15, but when I begin
linking a lot of tables together, I will occasionally get what seems to be
duplicate lines containing the same data. I am using Merant ODBC version
3.6, if that should make a difference.

Am I missing something pretty basic regarding SQL statements?

I've installed what I feel are all of the possible upgrades to CR, and
performed a registry hack that finally got CR to connect to the database on
our server.

I just feel there is something that I'm not doing or understanding
correctly.

For instance, when I look in the Data Dictionary, under Table Relationships
for Part, it says there is a direct relationship to PartBin. It says the
Primary Index is "PartWhsBinDimLo". Heck if I know what that means! The
fields used in the Primary Index are "Company, PartNum, WarehouseCode,
BinNum, DimCode, LotNum". I would assume that that means I must use those
fields to link Part table to PartBin table, right? Well, as far as I can
tell, the table Part only has "Company" and "PartNum" in common with table
PartBin.

Do I need to link the table Part first to table PartDim, and then link table
PartDim to table PartBin?

Oy! Any guidance is greatly appreciated!