I have now resolved the previous post issue listed below. Having tried three different make and size USB sticks I tried formatting to EXT4 from FAT32. It now has been re-booted many times and is still working after a Power manager shut down and wake up too. Tested with 2 of the previously failing sticks, I went through the same mount process's in all instances, dare I say QED!

Vix 3.0.404 issue
When my box came out of deep sleep this morning (first time on 404) it decided to use the 500mb USB stick as the only mass storage, adding a variety of directories! The hard disk is now not seen by the system information details it is only shows a 500mb device! So no access to recordings that are on the HD etc.
In System Setup the 500mb USB and 1TB HD are visible to format etc.
removing the USB and re-booting twice re-established the HD and the system put the epg in Flash as against the missing USB. I believe this also happened on 3.0.394.
This installation was from scratch i.e no backup restores of any kind.