iCal and Private Servers

Ok, here's the deal. I'm trying to publish some iCal calendars to my server. I can publish them via FTP directly from iCal and they are placed on the server just fine, I can see them when I look with my main FTP program.

Problem is, when I try to subscribe to a published iCal .ics file from another computer, it tells me "The data downloaded from ftp://www.xxxxxx.com.xxxxx.ics is invalid" and I get nothing. iCal sees the files on the server, it just won't load it. This even happens when I export the file and manually upload it to the server. I checked the read/write/execute permissions on the server and they are correct for these files.

Any clues?

EDIT: Ok, if I upload it via FTP manually it works when I subscribe to it. The issue seems to be that iCal uploads a file that has a size of zero. Still looking for any help on this one.