Surf Soho upgrade from 8.1.0 to 8.1.3 failed

Here’s what happened:
I logged into InControl.
Connected to the router,
Opened System, Firmware.
Clicked the Check Firmware button.
The message in the box said, New Firmware Available: 8.1.3
I clicked, Download and Upgrade.
The connection status went to Disconnected.
After a few minutes the status went to Connected.
But, the System, Reboot page showed that the router was running 8.1.0 instead of 8.1.3.
I clicked the button for Firmware 1: 8.1.3 build 5030 and clicked Reboot.
When the router came back up, the user’s PC had a good connection to the Internet, and the status showed that 8.1.3 was running, but after a few minutes, the router rebooted back to 8.1.0 and it has stayed there.
Did I do something wrong?
Or, what should I do next?

Check the Event log.