Pioneer DVD-RW DVR-118L

I recently replaced my optical drive on my G5 as it was not reliably burning DVDs. I ordered the Pioneer DVR-188L from New Egg after I did some research online. The drive burns great. But intermittently the drive won't eject and then the computer won't shut down. I tried zapping the PRAM and that seemed to work at least during my immediate tests. But if I put in a DVD and play it with the DVD player sometimes I can't get the drive to respond afterward. Then I force shut down and restart and then it will be fine. Is there some type of setting in the computer that needs to be adjusted or does this mean this drive won't work with this machine?