Files disappearing from home folders

I have students who save work to thier home folder and when they next logon a few days later the work is missing. I have checked the sessions to make sure multiple logons with the users id have not occured and have checked to make sure they have saved it to the correct drive. Could it be possible that the connection to server is lost during a session and the workstation still see’s the network drive and makes out it has saved to the share, but has not. Anyone ever had this problem? Any comments would be most welcome. 🙂