Unable to move files, asking for password

[JeffreyDriver]

Hi,

I have a really irritating issue with my NAS drive. When trying to move files around by dragging and dropping, Finder keeps asking me to enter my password and I do. The password is accepted, but the file isn't moved.

I can drag items from the desktop to the NAS drive, delete files and rename them. I just can't move them.

Any help gratefully appreciated.

EDIT:

It seems as though it's just the torrent folder that's affected, and there's some files that I can't even delete. Tried repairing permissions and doing everything I can think of but still nothing.

OSX 10.9.5
LinkStation LS220D (LS220D6F4)