No one has published a 100% fix for this.
However, it does tend to happen more when the 9200T is permanently left on. Use the remote's standby button after you have finished using it for the day. The standby button on the front of the unit can also be used.
Also use the Humax menus to format the drive next time this happens
1. Press the MENU button.
2. Select Record and press OK.
3. Select HDD Control and press OK.
4. Select Format and press OK.
NS, November 2012