Getting this problem myself, with drivers installed from Ubuntu Xorg edge PPA (i.e. very recent Xorg). I was assuming using this was at least part of the issue. You can see all the packages it updates from standard Ubuntu 12.04 here:
Quadro FX 880M
X.Org X Server 1.12.1 (Release Date: 2012-04-13)
Kernel 3.2.0-24-generic #38-Ubuntu SMP Tue May 1 16:18:50 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
The Xorg log after this problem shows nothing post suspend -- just the messages it gives when suspending. None of the other system logs show anything at all either.
Nvidia bug report attached if it's useful.