Readynas 312 network issues

We have 6 ystems connecting to a share on our ready nas 312 and up until about two weeks ago everything was fine.

The share is mapped to local systems as the "N" drive and everyone has read write access to the folder and sub-folders.

Now when accessing a file - we somertimes receive a lost connection to network drive message which happens if we are already in an open file or accesing a folder.  After 10 or so minutes access is reaqcuired and the file can be modified but it is making the system unusable.

We are updated to the most current firmwar and recently I feel the issue caused the volume records in the system to get wiped out and Netgear tech support had to remote into the system to correct.

Has anyone experienced this issue?