Just wanted to conclude this thread as it's been most enlightening.

thanks to all who helped!

the problem is thus:

modern systems don't just have one default graphics card that stays 'on'. They have a kind of power save function of only switching on when certain applications need them.

you can set a notification of this in the nvidia control panel where an icon in your sys tray shows whether your card has kicked in or not. You can also specify what apps use what graphics chip.

my issue was that vue10 refuses to accept my card as it's probably not supported. Vue is a pile of crap if it's not fully happy with all system fundamentals being quick and plentiful.

next mission is to see if there's anything i can do about that but I doubt it.