Here are few details: 1) I have installed laptop-mode-tools to enable auto-hibernation on low battery (and enabled auto-hibernation) 2) My system is encrypted 3) laptop is acer aspire 1 D257-13848
To test hibernation on command line prompt I call pm-hibernate (as root).
Most of the times wake works beautifully, prompting me for encrypt phrase and restarting properly. From time to time unfortunately grub menu is shown with 4 choices (linux, linux recovery, memtest). On grub menu, system does not timeout on 1st choice, but waits for manual selection. If the 1st item is chosen, it appears that it wakes up properly asking for encryption phrase and completing wake up.
Help would be appreciated.
(*) installing laptop-mode-tools does not make a difference for above.