Well, try newer drivers, then. I know that, with ff-7-, my 6600gt supports it just fine with the latest drivers. Try getting something in the 77.xx or 8x.xx and see what happens =)
They're talking about FF8 not FF7, just about any drivers should work on ff7 from what i've seen.
As for kyori_arg, so far no one here has managed to fix this problem, and there is already a thread about the black boxes problem
here.i would suggest to search elsewhere. It seems to be the whole 6 series that does'nt work with ff8.
A possible fix which i didn't think of before could be to uses wrappers. They can be a bit difficult to find so you will have to search around yourself, but basically what they do is emulate different video mode's
(Glide, OpenGl, DirectX9 ..ect) ... they are mainly used for old games like, forsaken, um.. cannot really think of anything else, basically mainly used for old glide app's.
Anyway, goodluck with the problem .. because like i said no one here has managed to fix it.