my webcam isn't working in skype. Cheesy works fine, takes photos, videos, everything fine. In skype, no, just a blank image.

my dvd/cd rom drive freezes up the system when used, cannot write dvd/cd if sometimes happens not to freeze my system (just acts like there's no cd in the rom... it sees it but the cd/dvd burner, both built-in ubuntu and brasero start writing images and advise me to insert a blank cd in order to write a cd and not an image)

random freezes when doing nothing important, like surfing the web, using chrome.

What should I do ? Any advice on any of this problems?