I just looked at the cable and I wonder if it even supports RGB. The following requirements are needed for RGB SCART:
1. SCART pin 16 must output a signal between 1-3V.
2. The Xbox must must be used in RGB SCART mode (1+2+3).
3. The TV must support RGB SCART.
Some AV packs will not set the mode to 1+2+3, thereby not generating a RGB SCART signal. To learn more about SCART, look
here.
Hey Zep...
After a few tests I realised the cable is faulty. I actually have to hold up the xbox end of the cable, and funny enough, it switches to Scart then. Lik Sang has apologised and assured me this is the first time it's ever happened. They've refunded my credit card. I've also just placed an order for the official Microsoft Scart cable.
Thanks to all for helpin me sort this out...