i have acer 5520g notebook with windows7 and ubuntu 9.10 operating systems. my dvd drive disappeared and i cannot found it anywhere on both operating systems although it's spinnig and its laser light winks. additionally when my computer boots, it says system bios shadowed, video bios shadowed, fixed disk blablabla (i cannot read that, it passes fast) what can i do to use my dvd drive again? thanks.