Are you sure it's an issue with the client?

Do other binary files of a smaller size get there?

If no data is getting there (0 byte file created), then it's likely an issue with needing to use passive FTP. If no file is created on the remote host, it could be any of a number of issues (authentication, permissions), but you should've seen an error message.

If the file is getting partially written, it could be a few different things -- disk quotas (possible), the link losing sync due to an excessive run of 0s (very unlikely, but can happen under some signaling standards over T1s), the connection dropping due to flow control commands (unlikely, unless you're coming over a modem using software flow control ... but you wouldn't be pushing 1.5GB over that)

...

Anyway, I don't think this is the problem you think it is, and I'd suggest you contact the helpdesk of your hosting provider.