SmartFTP and Excel 2007

Is anyone else having trouble using SmartFTP and Excel 2007? I was trying to upload some Excel files yesterday to a website using SmartFTP, and it does not seem to work. The files do appear on the site, but it seems that they are bing zipped/compressed automatically, and when I go to open them, all I get is garbage. They will not open as Excel files.

Can anyone offer any help? Please!!!