I get this too. I am using Kubuntu feisty and s2disk, (2.6.20-16-generic #2 SMP Wed May 23 00:30:47 UTC 2007 x86_64 GNU/Linux)
I even got it twice at one point (I had to bring up the system three times before it stayed up).
It may be related to removing power while the system is snapshotting.
I get this too. I am using Kubuntu feisty and s2disk, (2.6.20-16-generic #2 SMP Wed May 23 00:30:47 UTC 2007 x86_64 GNU/Linux)
I even got it twice at one point (I had to bring up the system three times before it stayed up).
It may be related to removing power while the system is snapshotting.