You can read bug #1573 which has been fixed on the topic. Is your download slow? Nautilus only start the mechanism after 5 seconds without any change so a slow download hanging could cause that sort of behaviour ...
-- Thumbnail settings don't work as expected https://launchpad.net/bugs/40874 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
