Q: sleep wakeup

Hello juergenfromkronberg,

Thanks for using Apple Support Communities.

From the description of the issue with your Mac where it is spontaneously restarting at sleep or waking up from sleep, it appears that your Mac may be having a kernel panic.  To learn more about kernel panics, including how you can troubleshoot them, please see the article below.

OS X: When your computer spontaneously restarts or displays "Your computer restarted because of a problem." - Apple Support

Take care,

Alex H.