Forgive me if this has been previously asked but I just got my IMac back from the "Shop Doc" - the internal CD/DVD drive is shot. I upgraded to Mountain Lion and had some problems with older devices. This has made me somewhat nervous about buying an external drive. I will still be obtaining work via CD so need to read and perhaps write - we also used our Mac to watch DVDs. Which drive would you recommend for/work well with Mountain Lion? (Not too $$ please...) I would prefer to order/pickup within Canada to avoid cross border charges. Many thanks!