I have a few data discs that i burned on my pc. My mac will not read them. I heard somewhere that the powerbook (it's a combo drive) will only read dvd-r's and not +r's. is this correct? I have some files that i would like to put onto my mac, and would like to know if i can just burn them on my pc and still be able to use them with my mac. I was also looking into the external lacie dual dvd+-rw drive for my mac that runs about $250. any input? thanks!