Acer Aspire 1551 Will Not Wake After Suspend
Solution 1:
i had the same problem, it's because of ATI graphics make sure you installed your drivers system -> administration-> additional drivers. the computer will search and refresh then install them. if you have already done this and the problem continues then go to the link, it helped me when i had the problem. http://ubuntuforums.org/showthread.php?t=1371844