After I upgraded to Ubuntu 10.10 suspend (both suspend-to-ram and suspend-to-disk (hibernate)) stopped working. A closer look at /var/log/syslog pointed to the tpm_tis module. The message was tpm_tis 00:0c: tpm_transmit: tpm_send: error -5 After taking a look at this post at launchpad I did the following: sudo gedit /etc/pm/config.d/unload_module Then I added the following line to the file: SUSPEND_MODULES="tpm_tis" And finally, not sure if it was necessary, I set the permissions to very loose. sudo chmod 755 /etc/pm/config.d/unload_module Now it works like a charm! -------------------- UPDATE March 1 2011 I said it works like a charm. This did not last. Performance was better than before, but the system hangs FAR more often than 10.04 ever did. I don't really know why. My guess is that it has to do with either VirtualBox or VMWare WorkStation, both of which I often have running vm's when suspending.