I had the same problem on a Dell Latitude D800 and what fixed it was the advice from Philip at the following link. I had to reboot for the changes to take effect.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/229806 -- Suspend/Hibernate Blank Screen https://bugs.launchpad.net/bugs/474568 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
