In that case I'd say it's a driver bug. It either really doesn't support larger than 2048x2048 or does but is reporting that's all it supports. That's what compiz is checking on the bit that fails, what the graphics card claims the limit is versus your current resolution.
In that case I'd say it's a driver bug. It either really doesn't support larger than 2048x2048 or does but is reporting that's all it supports. That's what compiz is checking on the bit that fails, what the graphics card claims the limit is versus your current resolution.