I'm not using ubuntu, but have the same bug on Arch Linux.
I think this is not fglrx bug - I have no errors about fglrx in logs.
I tried 2.6.39, 3.0-rc6, 3.0-rc7 kernels, but no luck.
With LTS kernel (2.6.32.43) the suspend/resume works stable (series of 10 tries sleep-resume was successful).
I'm not using ubuntu, but have the same bug on Arch Linux.
I think this is not fglrx bug - I have no errors about fglrx in logs.
I tried 2.6.39, 3.0-rc6, 3.0-rc7 kernels, but no luck.
With LTS kernel (2.6.32.43) the suspend/resume works stable (series of 10 tries sleep-resume was successful).