I had a problem with my Ubuntu 12.04 waking up immediately after going into suspend. I solved the problem by changing the settings in /proc/acpi/wakeup, as suggested in this question: How do I prevent ...
I'm using Ubuntu 11.10 on a 305u1a Samsung netbook with Radeon HD 6320 graphics. After suspend, my display stays black. The fans are starting and the harddrive-indication-light is working as well, so ...