Comment 2 for bug 792007

I can not prove this from your output but I had a similar problem and found that it was network manager doing the evil work.
What was happening was that network manager saw the system was going down to low power mode so disconnected the Ethernet, this leaves NFS with nowhere to talk to so NFS sits there waiting for the server to reply, the kernel grows a big queue and hey presto it looks like a hang.
If you get to the text mode screen using ctrl-alt-f1 or similar and get the network back up it can be recovered sometimes.

I just wish they would get rid of network manager and let the kernel do what it needs to during these changes in state.