This error message is generally due to a power supply issue where over time the 3.3volt level drops.
If the VG248 is observed to be operating normally, the messages are generally no cause for alarm, however in some cases users have reported the ethernet interface drops or the unit resets.
The issue is documented in Cisco DDTS CSCse83429.
Providing the unit is under maintenance contract, you should be able to arrange a replacement unit by opening a TAC service request.
