Crystal Report Help, please

I have been struggling with one simple report. I just want to have
a report showing how many units of each part have been ordered for
the last 8 months? We cannot count from Inventory because we are not
linking production to accounting yet.

I join 3 tables: Inv.Detail, Inv.Header and Customer, then pull out
part #, order quantity, customer name, invoicedate (with simple
condition), and most of all the sum of each part that have been

I used Merant ODBC and it works fine in connecting to the database in
Crystal Report. However, at the end when click to preview the
report, I got a message:

"ODBC error: [MERANT][ODBC PROGRESS driver][Progress]** unable to
understand after--"Declare". (247)" Then, another message:
"Error detected by DLL."

I called Merant c/s and was told to
download some patch from Seagate CrystalRpt. I did and get the same
old problem.

I tried Progress Report Design and could not find the function Sum or
Subtotal for each part#. Any help in either Crytal Report or
Progress. I really don't care which one if any of them works out
well. Please help.

Thanks a whole bunch.