Problem uploading themes

I am having a problem uploading new themes for WP. I have Wp 2.1.2 (that’s what is available in Fantastico). I’ve gone to the list of WP 2.1 supported themes, but when I upload them through my ftp, other than the screenshot, everything else shows up as 0 kb. I’ve gone in through my file manager in my cPanel, and am still only able to re-upload a few of the things correctly. When I go into the folder where the theme is on my desktop, they appear to be fine. Is there anything I can do to get these themes to upload correctly?

(Here is how I am uploading my themes: after downloading them, I unzip them. Then, I go into my ftp (filezilla) and upload them by dragging and dropping into the themes folder.)