DSM-G600, DNS-3xx and NSA-220 Hack Forum

has some days that my dns 323 nas not show me some directory I tried both of these mounts in my fstab:

# NAS
Mnt/HD_a2 192.168.0.13 / / media / MS nfs rsize = 8192, wsize = 8192, timeo = 14, rw, hard, intr 0 0

or

Mnt/HD_a2 192.168.0.13 / / media / nfs MS users, rw, auto 0 0

but the result is the same when I access the folder shows me some direcopty and others are not visible, if I access the NAS via ssh and shell and do an ls of the directory later by the invisible becomes visible mint ....

how can I fix this?

thanks