Can't open data socket

When I try to upload a file, I get the following error;

257 "/home/tyler" is current directory.

STATUS:> Sending arcsetup.exe

COMMAND:> PASV

ERROR:> Can't open data socket

STATUS:> Failed to send C:\arcsetup.exe

Some people say it's with my llinux masqerating box, but other people say it
is with passive mode. So i turned off passive, and still get a error. Has
anyone sucessfully fixed this?

-Tyler