After a month of tinkering I seem to be able to manage this problem but there is still an underlying issue that causes the problem of Resume of Sleep to re-occur.
I've found that it doesn't matter which Nvidia driver I use - both 314.07 and 314.22 now work.
What matter's is *how* I install said driver. If I use the default install method for the Nvidia driver then all is well but if I use a custom installation and don't install the 3D driver software (which I don't use) or the Nvidia Update software then the problem will happen and the TBS card will disappear from Device Manager when I 'Resume from Sleep'.
I also found after a couple of weeks of problem free usage the problem re-occured (following a WIndows Update I think) but by completely uninstalling the Nvidia software and reinstalling it - all was fixed again.
That would *seem* to point the finger at my graphics card maybe in combination with the mobo but that would be too simplistic because the *only* device that disappears from Device Manager is the TBS 6280 card. This, in my opinion, makes TBS claims that the Sleep issue within their drivers is fixed - a premature claim.
TBS needs to talk to Nvidia about how this can happen - I will post on the geforce forums as well.