I observe the same crash on a 3.2.0-31-generic kernel running as a Dom-U on XEN. On another machine running 3.2.0-30-generic (without Xen) it works just fine. nfs-common version is the same as yours on both machines.
I observe the same crash on a 3.2.0-31-generic kernel running as a Dom-U on XEN. On another machine running 3.2.0-30-generic (without Xen) it works just fine. nfs-common version is the same as yours on both machines.