I've spent a few hours going through similar questions, and found answers ineffective or beyond my comprehension. Beginner user. (1yr)
Suspend began failing after my last update. (Feb 2013 - Not sure which - it was a routine bundle suggested by update manager.) Entering suspend mode is successful. When attempting to wake, computer begins running and keyboard backlight comes on, but display remains black. Only option is hold power key and shut down.
Entering password, and combinations of ctrlaltFkey have failed.
I dug through through ReportingBugs on help.ubuntu.com for a while, but the material is more dense than I can navigate.
Ubuntu 12.04 LTS
Processor: Intel® Core™2 Duo CPU P8700 @ 2.53GHz × 2
Graphics: VESA: NVIDIA GeForce 9400M
OS type: 32 bit
2009 13" Macbook Pro