Asdlolciterquit: thanks for the link. I'm sure it will be useful when I come to tune my card.
 To your other question, my GPU setup just has 1 project, Docking@home. My CPU mining is successful on my laptop with 3 projects but I don't think increasing the number if projects on my desktop will affect this. Can anyone shed some light on why I have gone 48hrs without mining a block? Is it my config file(s) or does my card have too low a hash rate to expect a return in that time period (see post above)?

Edit: I'm pretty sure it's not my hash rate unless I've been particularly unlucky