Has anyone else experienced this problem? I'm using a PowerMac G5 with the new superdrive and I can't get it to burn DVDs at 8x using Toast 6.0.3. It pops up with an error message that says something like buffer underrun, but I've checked off the option to prevent buffer underruns. I can burn DVDs great at 4x but I was hoping to use 8x. Is this a Toast problem or have others had problems with their superdrives?