I have AC Ryan HD with 2 TB. Recently i upgraded to latest firmware. After that I noticed frequently hang. This morning I tried HDD Fix errors option after that I noticed many of my movies are missing from the folder roughly more than 100 movies.

Is this is a bug ? Anyway to recover what is lost ?

CHKDSK your hard disk with the Playon connected to your PC via the USB cable.

Recuva (google it, makers of CCleaner) can undelete files, it's free and a portable version is available. Chkdsk might mess up your drive even more, it is hard to control what it's doing. Wasn't the HDD fix option in the player supposed to be the equivalent to chkdsk in Windows?

The NTFS (or something else) driver is extremely unreliable. Please don't trust *any* file that you have written to it. As it is unpredictable where it fails, nowadays I write a bunch of files using windows XP; do a chkdsk before and after. To some extend this looks like a "workable" situation. Problem seems to be that the driver only supports a part of the NTFS specification (and yes - this spec is not "open") (eg look what happens if you "share" the disk and again unshare it using windows XP: it will make the shared folder unaccessible from windows and you think you have lost all files. Re-sharing it again will fail; but will set things straight, assuming you did not access the previously shared folders before).

(to be honest: this is one of the most unreliable implementations I have ever seen - I believe there are earlier threads about this horrible file system behavior) Samba and the file system driver should be reliable; I don't care to much about the other things (apart it should play all video and audio files)

There is a new beta firmware for the newer models with a new NTFS driver. No updates for the HD1 and Mini1 so far, but this was promised. I guess they wait for some feedback, if it's OK compiling the new firmware should be straightforward. Ext3 filesystem (search the forum) might be an option, but far from ideal for Windows users.