DVD plays on 23in LCD in X but not 9

[Simon Chapman]

I just linked up my new Cinema Display to the 15in 1Ghz and 'tis a
wonderful thing. And yet.... I'm in 9.2.2 most of the time and I couldn't
get a DVD to play on the Cinema Display from 9 - I got the DVD Player
controls and I got the audio but no picture. I rebooted into 10.2.5 and it
played fine. Any idea why? I'm using the Apple DVI to ADC adapter and DVDs
do play in Os 9 when I'm watching on the TiBook's built-in screen. TIA.

Simon