I updated the BIOS after installing Win8 x64 succesfully,then I reinstalled Ubuntu 14.04.1,I am happy to report that the shutdown prolem is finally solved,thanks a bunch :)
although the BIOS update succesfully solved the situation,I will still post the outcome of dmidecode -s bios version and dmidecode -s bios-release-date
I updated the BIOS after installing Win8 x64 succesfully,then I reinstalled Ubuntu 14.04.1,I am happy to report that the shutdown prolem is finally solved,thanks a bunch :)
although the BIOS update succesfully solved the situation,I will still post the outcome of dmidecode -s bios version and dmidecode -s bios-release-date
V1.10
10/24/2014