I have this showing up in my logs at startup of the DNS-323.
it only shows up on startup. i can log in, out change settings around and nothing happens with the log that shows any new "fan can't stop, check it please" message.
I can adjust the fan speed setting, from auto to always on, and the fan responds by running fast, then slows down but not off. and for auto, it just runs on low.
i have my hard drives set to sleep after 5 minutes, but fan stays on low anyway.
that's my description. is this an issue with the firmware? can alt-F fix this? D-link has not that i know of.