Surprised to find that ASUS are shipping me another motherboard of same model - as mine is within the warranty period.
I was perfectly happy with the single card I had - and will go back to that, whilst using the new PCI card to run a third monitor (just because I can).
Thanks for your comments folks.
I'll look into bigger cards - but have no growls at my 40 fps rate on Second Life.
Ah...the trubbles of a furry, eh?
=^..^=