I attempted to flash the new Vix Image 5.2.002, first disconnecting my USB attached HDD (storage), and using a formatted FAT32 8GB stick and following the recommended procedure(***see last lines). It was impossible to get the box to boot itself from the USB stick. After several attempts I decided to use Image Manager to restore an Image from the USB stick. This could not be achieved either.
I am thinking there is a bug somewhere, so tried the following:-
Re initialised the USB stick in Setup> Storage > Initialise:
Created fresh backups in Backup Manager and Image Manager.
Viewed the newly created backups using "list".
Both the .gz (system backup) and the .zip (image backup) were listed in /media/sda1/ which I assume is the USB stick.
I then attempted to restore both these files using Image Manager and Backup Manager respectively.
Image Manager showed the .zip Image backup file in /media/sda1 however the Restore button was not enabled. For this screen, the VIX Manual v1.1 text states the yellow button = Restore, whilst the image shows blue = Restore and Yellow = Download. On my box Yellow button = Download and Blue button is not enabled. With .zip Image selected, neither the Blue button, nor OK has any effect. The MENU button shows a blank SETUP screen which is empty with Red/Green as Cancel and Save.
Likewise it is impossible to do a Restore from the .gz system file within Backup Manager.

Am I right in thinking Flashing a .zip image by booting from the USB stick is the same as Restoring a .zip image within Image Manager? Then if I solve the inability to Restore my existing System and Image files from the backups I created, I no need to worry why the box will not boot from the usb stick. I would simply place VIX 5.2.002 .zip file onto the newly formatted USB stick and use Image Manager.
(***) I did read the "How to Flash to TM-TWIN-4K.pdf" which advises to unzip the download and place the entire contents in root of USB stick. I did try this initially, which created /update/tmtwin4k/xxxxx files (5 totally).
I also tried placing the .zip file in root of usb stick, and the five xxxxx files themselves in usb stick root. Then I tried the same copying to usb stick \update\. None of these worked either.

Meanwhile the box is working fine on my out-of-the-box version 5.1.032