Thanks Armand & Filark.
@ Mokel22 - GOOD! Your mp3 works very well.
I learn how using Winamp for hibernation's issues.
For now I tested only for 10-20' and it seems to prevent blocking device after closing.
Now I want to try for some hours.
Only little thing is that it seems to warm a little (only a little on the top pf the e-reader side, maybe CPU is there).
However i think that it shall confirmed situation (also for drain of battery), this work around is excellent.