LS410D0201 has to be reset often in order to be seen

[southerntierpc]

I have purchased 2  LS410D0201 for use with a couple of my clients.  The problem is that they both have to be reset / powered down and back up in order to be seen on the network.  These units are both mapped and are being used for daily file storage and retrieval.   They are both mapped and the mapped drives are linked to Documents Library so that anything saved to Documents  is automatically saved to the NAS.  All systems for both clients have windows 7 pro.  Each of these NAS are at a different location and different networks.  One client NAS' firmware has been updated.  The other client, the newest NAS, has not yet been updated.  Plan to do this tomorrow.
Any suggestions would be welcomed.
UPDATE: 
The client with the un-upgraded firmware failed when trying to upgrade with an ACP error.