Sales Tax Liability Report

My sales tax liability report is not populating correctly. Last quarter was fine - showed gross sales, non-taxable sales, and taxable sales. This quarter the report is messed up - the numbers don't even makes sense - it shows my taxable amount is MORE than my gross sales and it shows nothing for non-taxable ... What went wrong here ???

Use this report to determine the amount of use tax you owe to each tax authority for invoices you enter during a period. The report lists in summary or detail the total amount of tax you owe for each tax name on invoices you enter between two dates you specify when you submit the report