Recently I got a Pioneer DVR-107 to replace my 4x DVR-105, and the media I used on my 105 no longer works on the 107. I used to use DVDPro 4x media, but it fails every time in the 107 when I burn at 4x. If I burn at 2x, it's fine. I tried a blank Taiyo-Yuden 4x DVD-R from work, and it too failed at 4x. Must I use 8x or <4x media for my new 8x drive? I might try some other 4x DVD's, but this is disappointing. I'm using the latest version of Toast, by the way, so that shouldn't be an issue.