Job Report Totals

Hello

Can you please tell me how the Job List  report is calculated?  I understand that it should show the profit or loss for the job.

My job list report shows one total but the consolidated Profit and Loss statements for each of the years show a different profit amount?  I push the Job Profit and Loss statements into Excel and recalculate.  Total up the years.

I have checked all of the chart of accounts totals in the Job Profit and Loss statements to the 

Job summary reports and they match.

What could be something / s that I can check to try and match both reports?

Thanks very much.

Heather