Ah excellent ideas
The texture seems ok so stressing out the gpu seems to be the case. Card has 1 Gig (although I'm also loading a lot of other fairly large textures so I'm probably getting close to the 500Mb mark).
Tried switching to DXT for the huge textures (or any large textures for backgrounds which I thought should be a bit lossy anyway) -- IT WORKED!
Quality is still very good!
If I could hug you right now I would.