I can confirm this issue on my Z61m.
My daily work is a lot smoother with suspend working.
I would like to switch to the open source driver, but that is not an option, as the X1400 in Z61m is not supported by that driver. Right?
I have made the experiment of rebuilding the 2.6.22-12 kernel, the modules and restricted modules, changing from SLUB to SLAB. With this setup suspend works. Unfortunately the system is not stable after resume, but that may be an effect of something else being changed by the custom building of all those modules. Building the custom kernel was quite a lot more work than I expected, and the documentation on how to do so is somewhat sketchy - I did something along the lines of https://help.ubuntu.com/community/Suspend2Kernel.
So, are we out of luck until ATI fixes fglrx? What are the chances of X1400 support in the open source driver?