Below is the System Diagnostic Report related to the Sleep Wake problem:
10/18/14 11:18:31.411 PM discoveryd[48]: Basic SleepProxy BSP Server Disabled. Metric = 3373
10/18/14 11:18:31.425 PM discoveryd[48]: Basic SleepProxy Could not get the primary interface
10/18/14 11:18:31.427 PM discoveryd[48]: Basic SleepProxy Sleep Proxy Server is not enabled
10/19/14 12:24:56.163 AM coreaudiod[226]: 2014-10-19 12:24:56.163308 AM [AirPlay] Power: SystemWillSleep
10/19/14 12:25:14.000 AM kernel[0]: ARPT: 4027.268034: AirPort_Brcm43xx::powerChange: System Sleep
10/19/14 12:25:17.000 AM kernel[0]: RTC: Maintenance 2014/10/19 06:13:11, sleep 2014/10/19 04:25:17
10/19/14 2:13:11.000 AM kernel[0]: Previous sleep cause: 5
10/19/14 2:14:01.000 AM kernel[0]: ARPT: 4080.372655: AirPort_Brcm43xx::powerChange: System Sleep
10/19/14 2:14:05.000 AM kernel[0]: RTC: Maintenance 2014/10/19 08:01:59, sleep 2014/10/19 06:14:05
10/19/14 4:01:59.000 AM kernel[0]: Previous sleep cause: 5
10/19/14 4:02:55.000 AM kernel[0]: ARPT: 4140.796518: AirPort_Brcm43xx::powerChange: System Sleep
10/19/14 4:02:58.000 AM kernel[0]: RTC: Maintenance 2014/10/19 09:50:53, sleep 2014/10/19 08:02:58
10/19/14 5:50:53.000 AM kernel[0]: Previous sleep cause: 5
10/19/14 5:51:43.000 AM kernel[0]: ARPT: 4193.910649: AirPort_Brcm43xx::powerChange: System Sleep
10/19/14 5:51:48.000 AM kernel[0]: RTC: Maintenance 2014/10/19 11:39:42, sleep 2014/10/19 09:51:47
10/19/14 7:39:42.000 AM kernel[0]: Previous sleep cause: 5
10/19/14 7:40:37.000 AM kernel[0]: ARPT: 4254.089380: AirPort_Brcm43xx::powerChange: System Sleep
10/19/14 8:12:00.000 AM kernel[0]: Previous sleep cause: 5
10/19/14 8:12:02.118 AM WindowServer[114]: handle_will_sleep_auth_and_shield_windows: Reordering authw 0x7f90825850f0(2004) (lock state: 3)
10/19/14 8:12:02.118 AM WindowServer[114]: handle_will_sleep_auth_and_shield_windows: err 0x0
10/19/14 8:17:31.000 AM kernel[0]: Restarting to collect Sleep wake debug logs
10/19/14 8:18:30.000 AM kernel[0]: ACPI: sleep states S3 S4 S5
10/19/14 8:18:30.000 AM kernel[0]: Sleep failure code 0x00000000 0x29006c00
10/19/14 8:18:30.000 AM kernel[0]: System was rebooted due to Sleep/Wake failure
10/19/14 8:18:39.454 AM discoveryd[48]: Basic SleepProxy BSP Server Disabled. Metric = 3373
10/19/14 8:18:39.469 AM discoveryd[48]: Basic SleepProxy Sleep Proxy Server is not enabled
10/19/14 8:18:55.652 AM spindump[182]: Saved diag report for Sleep Wake Failure version (null) to /Library/Logs/DiagnosticReports/Sleep Wake Failure_2014-10-19-081855_Witolds-Mac-mini.diag