Sounds like an issue with permissions or ownership on user's
directory, and all child directories under it. I've had this issue myself before. You would need to run something like these while using said user with issues:
chmod -r 755 ~/torrents/rtorrent
*This will apply read write privileges for all folders and files under /torrents
chown -r user:user ~/torrents/rtorrent
*applies ownership of all folder and files in /torrents to "user"
It could also be an issue with Rutorrent folder in your web directory under
it should read something like:
drwxr-xr-x 11 username username 4096 Apr 8 13:51 rutorrent
if it doesn't you will need to run:
chmod -r 755 rutorrent
chown -r user:user rutorrent
I'm pretty new to linux myself still, so if anything is wrong here, someone please correct me.