system freeze upon insertion of blank DVD (dual layer)

system hard lock few seconds after i insert a new blank dvd (dual layer) in my drive.
it worked fine last week, (from intrepid ibex) before i update to jaunty.
it worked on hardy too and earlier.
harware didn't change, only thing that changed is the upgrade to jaunty.
when the system freeze, numlock and caps lock aren't responding, neither crtl+alt+f1,f2.. nor ctrl+alt+backspace.
it seems completely frozen.
even if i insert the DVD in the drive before the system boots up, i can login gnome, i see my desktop,
but then everything is frozen. eache time i try to put a dvd in the drive i have to hard reboot the machine ..

my system doesn't have much to overload the psu: i just have HDD and DVD drive.
i use onboard gfx,sound and net chip.

i include hardinfo report.

(hardinfo should be included by default it's great)

tnx for your attention