I have a 2012 13-inch MBA and it has difficulty waking from sleep. It uses OS X 10.8.x I am able to wake it from sleep twice using these methods. First repeatedly while holding for 1-2 seconds down the power button for short periods of time and then repeatedly while holding down for less than 1 second down on the power button. The 2nd method recharging the MBA. Should I update to OS X 10.9.x? Would this resolve this issue.