I know it's late. But i think i found a solution for MM setup with refresh rate below 60Hz.
I don't have MM setup, but i can force my monitor to display 5760x1080 at 22Hz. It's just for testing...
As you know Dead Space does not allow to set resolution with low refresh rates.
But i managed to fool the game with GeDoSaTo tool.
I enabled 5760x1080 @ 60Hz, and instead of downscaling to 1920x1200, i told gedosato to output at 5760x1080 @ 22Hz.
And Bam! Dead Space can now see the resolution 5760x1080 @ 60Hz
screenshot taken with msi afterburner, not with gedosatos!
rendered on C2Qq9300@3GHz and GF GT 640, fps seems to be limited by 22Hz. At 3840x2160 in this small scene im getting 26fps (max settings). I thought framerate would be much lower 
So, yeah, it's working
link for gedosato
http://blog.metaclassofnil.com/?page_id=582