can't change the download dir to somewhere in /usr
 

I think this is a really strange thing in LimeWire 1.6 running on RedHat Linux 7.1. Actually my download directory is located in /home/jon/downloads and the incomplete dir is at /home/jon/Incomplete. I wanted to change that to /usr/temp and /usr/temp/Incomplete because /usr is on a larger partition. But when i tried to do that i get a: "Invalid location for storing files. Please use another directory or revert to the default." I get the same at every directory in /usr. I also tried to add/remove the ending / but that doesn't work either. I have read/write/execute permissions in the directory...
Maybe someone can help me out with that?

Jon