I have the same problem with my E6400 when trying to go into standby or hibernate. I've installed many updates and also terminated many processes without success. However, I have found a repeatable scenario. If, right after startup/logon, I choose Hibernate immediately while things are still loading, it will hibernate. Then, after resuming/restoring, I can hibernate as normal, and the system no longer hangs. So the trick for me is to go into hibernate immediately after startup and then I can