The majority of the "cheap" dvd-r discs can be a problem for devices with a weak laser. There are certain brands of dvd-r that my ps2/xbox/home dvd player can't read well (extemely long loads, skipping, bad burns, errors when streaming info, etc.) That usually isn't a problem with computer dvd-roms though. IMO the best brand of dvd-r i have ever used is verbatim datalife plus. It's the only media i have used that has worked 100% in every device i have, and i've used maybe 10 different brands of the cheaper stuff.
Apple suggest..well of course their dvd's ( surprise surprise) or to use the song dvd but those happen to be the most expencive blanks out on the market. ( i know cuase i had a problem burning dvds with my Pbook. i have switched to verbatims aswell and havent had many issue with them...a couple medium errors but that could just be a issue with the disc im using. i have a Rev A albook so i have the first superdrives..so that probably doesnt help my situation much either