Hibernate does not work on my Lenovo W520 laptop. The computer freezes with the error message
[ 6218.321519] ACPI: Unable to dock! The number in the square brackets can be different each time. The Ubuntu is version 10.10. Does anyone know how to fix the problem? Thanks!
First, I suggest you update your Ubuntu to 12.04 and try again. A lot of enablement work for systems with Ubuntu preinstalled is rolled into new releases, so there's a good chance it may work then.
Second, I think I've seen reports about the W510 only being able to suspend/hibernate if you install the proprietary NVidia drivers. You may want to also try that if your W510 is Nvidia-equipped.