Comment 5 for bug 136688

In these situations I usually try a manual sleep and monitor the script as it runs.

Firstly I edit /etc/acpi/sleep.sh and add "set -x" at the start of the file. Then I switch to a virtual terminal and run:

$ sudo /etc/acpi/sleep-sh force

And monitor the output. If there are problems with the screen blanking and not restoring, I use:

$ sudo /etc/acpi/sleep-sh force >/tmp/sleep.log

or, if the PC locks up and has to be reset:

$ sudo /etc/acpi/sleep-sh force >/var/log/sleep.log

If you could try this maybe we can determine if the issue is in gnome's power-management handling or is a wider problem.