when I close the laptop lid and then open it after sometime, I see the message on my screen saying "Failed to suspend". What is the problem while the laptop is trying to suspend.
Finally I was able to resolve the problem by installing acpi-support from the ubuntu software centre. Here is the thread that helped me http://ubuntuforums.org/showthread.php?t=1608752
This was the cause of problem Hibernate and Suspend do not exist anymore, help.