I am backing up large files to the dns-321.  I have a unit with latest firmware, and the drives have updated firmware.
I have mapped the drive using the d-link utility.  
Sometimes the drive becomes unavailable during large file transfers (mainly hi def files captured with my hi def tv videocard).  
I tried changing the temperature setting, and this helped a bit.
Any thoughts as to what might be going on?  The OS is XP.
By the way; in updates; we should be able to change the temperature setting without setting up email notification.  Actually, I don't think the notification will work in my setup (none of the tests worked) but I think the unit took the new temperature setting.
Thanks.