I encountered the same problem yesterday after I upgraded my twonky install to 5.0.46, 4.4.11 was/is working fine. After a couple of minutes the NAS "unmapped" itself and seemed to have stopped working. I also got pink LEDs on the DNS-323.
After a quick google search I ran into this post: http://forum.dsmg600.info/t3726-Pink-le ... e-possible
To put it in a nutshell: "As I use Twonky, I think that it starts on boot, and tries to write everything (config, database,...) in /home/root/.Twonkymediaserver, and it fills the whole filesystem."
They also go on to describe two different ways of fixing the problem, once after the fact (i.e. installing twonky) and one before. I went back to 4.4.11 which runs stable.
Hope that helps...