.csv users --> Win Server 2003

Dear Sages,

Any secrets out there? I'm trying to import 400 users into my domain (Win 2003 R2) and I've set up the spreadsheet exactly according to the directions (i.e. - deleted all extra rows, headings, labels, etc.), saved the darn thing as .csv, run addusers.exe and my Command Line STILL tells me:

Error in input file. Found data before [Users], [Global] or [Local] sections

I swear, I open my list in NotePad and there's NO extra data in there! What mistake am I making?

Thanks as always,
Brooklyn Lev