csv File from Mac (via Excell) different than made on PC??

Hi,
This is my problem.
I am exporting a file from QuickBooks to Excell.
Then save as CSV.
(I made sure not to use any special character.)

I try to upload it to update a db online.
the file type is not recognize.

If I open it on a PC, via Office 2007, then save it again, then I am able to upload it.

What is the difference between these two files? They look absolutely the same.

I even tried to open the Mac file using OpenOffice.org. It open perfectly, however when I try to save it as csv, it warns me that the file has not the right format.

Please let me know if it makes sense, and if you have any clue.
Thank you very much.
Regards

 

Thank you for your link, but my question called for a more complicated answer.

Again, the format created by Excel (Office 2008) CSV is somehow different than the one created by Excel 2007 (PC). This difference not perceptible make the system not recognize the file.

Thanks for your tips.

ps, it might have to do with the web app. the routine checking/validating the file format before uploading the file