vTiger 5.4 - cutom Reports duplicate records with invoices with more than 1 item

[motty.cruz@gmail.com]

A custom report is generating duplicate records for invoices with more than one item. For instance, if I have a invoice with the following items I sold to my customer. PC for $550,
Printer for $50
software for $100.

When I generate a report for the month, it will show a total of $2,100 Although the total should be $700.

I am using vTiger CRM 5.4.0; has anybody seen this problem before? any ideas how to solve it?
(Selected Fields) for Report are:

Organizations Sales Reps
Organizations Organization Name
Organizations Serial No.
Invoice Work Order
Invoice New Serial
Invoice Date
Invoice Total
Invoice Monthly(If Applicable)
Invoice Product Name
Invoice Quantity
Organization Lead 1
Organization Lead 2

Thanks in advance,