I have the same problem and I just saw that they fixed a bug in a library used by SleepyPi

More specific, the RTC library file DS1374RTC.cpp reads since March: '2015
(which is after the question was asked)

Releases
========
V1_0 - 10 Aug 2013 - Initial release
V1_1 - 11 Mar 2015 - Mod: Added "ackAlarm" and "ackRTCOSF" functions to aid Alarm use
- Bugfix: Changed the way the "SetAlarm(tmElements_t &tm)" was updating
the Alarm time. It wasn't mapping correctly

I have the same problem and I just saw that they fixed a bug in a library used by SleepyPi

More specific, the RTC library file DS1374RTC.cpp reads since March: '2015
(which is after the question was asked)

Releases
========
V1_0 - 10 Aug 2013 - Initial release
V1_1 - 11 Mar 2015 - Mod: Added "ackAlarm" and "ackRTCOSF" functions to aid Alarm use

• Bugfix: Changed the way the "SetAlarm(tmElements_t &tm)" was updating the Alarm time. It wasn't mapping correctly

They also added a new example to wake up the Pi: WakePeriodicallySimple.ino