Problems since Maverick : My screen goes black and never come back (need reboot) and sometime my sound just stop working (need reboot) : these 2 problems are not related to each other.

Since I installed Maverick, there's two major problems ocurring !!

Problem number 1 : It happened to me 3 or 4 times yet, the sound of my macbook air just stop working... no more sound comes out ! Not even the F11 or F12 sound when you play with your speaker. Nothing goes out of my Mac, I need a reboot, then it works fine again !

Problem number 2 : When the screen is going to sleep mode, it will sometime stuck there, it is impossible to wake up the screen. But, the keyboard seem to light up, but the screen won't respond and stay black, so I need to force a reboot.

I got the latest macbook air 2013