Update :- In fact you can use a GTX275 now! Probably old news to you all, but netkas.org has an installer package and link to 2xx drivers (use the one from the comments - macpro check disabled).

At least something good has come out of my tireless searching!

So now I have a mac with a fully functioning GTX275 - *Still* no solution to this stall problem... it's bugging me now!



Cheers,

Jon.