Do as follows: -

1) Fresh flash lastest build 632.
2) Straight after completing the startup wizard re-initialize your HDD. Menu > Setup > System > Hard disk > Initialize. Exit out of all screens and wait for the pop up window saying 100% complete.
3) Do not restore any backups or install 3rd plugins, especially TSpanel. Only install a softcam if you use one.

Once setup, reboot, hold down standby button on remote and select restart. Check HDD is mounted to /media/hdd, blue button > ViX > Mount manager.