Yes, I have "Header fields on each record" selected.

I am importing from Excel, so the length of the invoice number shouldn't matter.

Because 3020 is a GL acct code and WATR is a distribution code I'm not quite sure how to line up the information on the spreadsheet. I've looked at the sample data (APINV.xls) but it isn't any help at all.

In Excel my data is laid out as follows:
Line 1:
Column A: H
Column B: AGAPPE
Column C: IN
Column D: 39034
Column E: D
Column F: 1 (Det-Detail Type)
Golumn G: 3020
Column H: (blank)
Column I: (blank)
Column J: 48.00

Line 2:
Column A: H
Column B: AGAPPE
Column C: IN
Column D: 39034
Column E: D
Column F: 3 (Det-Detail Type)
Golumn G: WATR
Column H: SW
Column I: DEMO
Column J: 800.00

I've tried moving the 48.00 on line 1 from Column J to Column H, but that doesn't work either. I'm determined to make this work, although I could've easily just manually entered all of the invoices in the time it's taken me to not figure this out yet. Now it's the principle of it....I must make this work.