Here is what customer service at Emerson sent: DVD-R 4x can be used 8x or higher will result in a disc error. DVD-RW 2x can be used 4x or higher will result in a disc error. The following discs have been tested and are proven to be compatible with our DVD recorders. MEMOREX DVD-R FUJIFILM DVD-R FUJIFILM DVD-RW IMATION DVD-RW IMATION DVD-R 2.0 TDK DVD-RW 2X TDK DVD-R 2X The following are brands of discs we DO NOT recommend: MEMOREX DVD-RW SONY DVD-RW SONY DVD-R TDK DVD-RW 4x TDK DVD-R 4x I have 2 questions: 1. Does anyone agree or disagree with the compatible and not recommended list, and are both consistant with each other? 2. Do one or both lists change or stay the same after the firmware upgrade is finished, and does this upgrade only apply to -R and not to -RW? Thanks - ROB.