Can't upload large files

[al bett]

I am having a hard time uploading large files. I have
high speed internet through COX. When I try to upload a
large picture file to my web site using FTP Pro it won't
go through. Also, I have tried to upload a newsletter
with pictures in it to my printer who has a web site that
allows you to send a file. The attachments (newsletter
with pictures) won't go through. COX says everything is
fine on their end.