z97 extreme 6 M.2 windows 7 64 bit hybrid sleep failure

[Kitaek Lee]

Hello,
I try to hybrid sleep with below system.
But, It always can't wake up. It goes to system reboot.
Sleep and hibernation works fine seperately but only hybrid sleep has this problem.
I try this using ASUS Z97 as well but there is no problem.

system info.
asrock z97 extreme 6
windows 7 professional K 64 bit service pack 1
storage : only M.2 SSD