3548P changes not saving

Hi all,

We just bought a PowerConnect 3548P. I configured an IP address, user name and password on it through console then configured it using web console. I unplugged the power afterward. I found all the configuration (settings after initial setup via console) are all gone. I started again but this time I just changed the Time sync, powered it off and on again... Time sync settings reverted.

Did I miss something. Why the settings done via console are not saving?