After a few days working ok with navigatrix, (after discover how to boot disabling UEFI and Secure Boot), yesterday, suddenly navigatrix didn't boot from my usb pendrive.
I tried the same pendrive with a Compaq Mini with XP x86 in de HDD and it works fine.
Take a look to the BIOS in order to see if there is any change and all is like before (CSM boot with Secure Boot disabled and the boot devices in correct order 1.USB 2.DVD 3.HDD)
Tried to boot from another distro with a dvd and it boot fine.
I made a pendrive with navigatrix again (same pendrive), with the new september distro, checking md5sums and its ok but din't boot again.
At this point I don't know how to do, no more ideas.