[n3rd4i]

@hawhill, knc1 and twobob: Thanks for the explanations.

Indeed the problem was Duokan instalation. I've tryied to use "DISABLE_DUOKAN" in rootfs to make the boot sequence clean for KindleOS but with no success, I think its because I used the latest Duokan 2013 and this disable is no longer supported.

Another curious thing is the following behavoir:
- after a restart the boot sequence shows the menu to choose the OS
Option1: if I press "Z" = KindleOS (or just wait because of the default OS selected to KindleOS) after the system loads, the Exp Browser does not work.
Option2: if I press "Q" = DuokanOS, then in the main menu i go to system, then i use "Switch to Kindle" functionality, after the wait, the KindleOS is loaded up, the menus are very very slow, and suprisingly i can use the exp browser...

This i didn't understand, the option1 boot makes KindleOS work fast but no Exp Browser makes the system unfunctional, but if you chose option 2 the result KindleOS system works very slow, but the Exp Browser works.

So i decided to uninstall "DuokanOS" it from the main menu.
Now KindleOS works as expected. I will just stick with KindleOS for the moment.

I was thinking of installing an older version of DuokanOS (maybe latest 2012) to support DUOKAN_DISABLE functionality, but this is offtopic to this thread so i will stop disscussion this here.

Thanks again.

Edit: don't move the posts here, i will start new ones there if i will try this older version, thanks for support. The only good thing about this DuokanOS is the Cut Functionality of the PDF reader, exept that, you have no real advantage, and its crawls of python scripts, and this seems uses allot of memory