Purchased a MATSHITA DVD-RAM UJ-845S and installed in my PowerBook G3 Pismo with 384 SDRAM, 40 G hard drive, 500 MHz processor, running OSX 3.9. Burns CDs in iTunes just fine, but insert a blank DVD-R and no icon appears on desktop. iDVD 4 came with OSX 3, but I'm not even sure I can load it...