That didn't help. I'm going to zip up and send you the code via email.
Also, please note:
The line of code that's having a problem is:
GetInvPercentages(Convert.ToString((xlRange.Cells[rCnt, 4] as Excel.Range).Value2), ref upcharge, ref margin);
The following line of code does NOT have any problems:
GetPercentages(itrDepartment, itrSection, ref upcharge, ref margin);
I wonder if it has something to do with the call to the spreadsheet. What do you think?