If you are using firmware 1.55 STABLE or below and Grand Theft Auto: Chinatown Wars doesn't load, but instead shows two white screens, try disabling battery saver in the Settings/Misc menu before running the game.
Alternatively, you could just upgrade to the latest stable firmware, which at this point in time is 1.61 STABLE.
• Using your CycloDS Evolution for the first time
• Trimming Types - Safe and Aggressive
• Dump your DS/GBA games
• Can I play GBA games without a Slot-2 device?
• GBA Flashcart Compatibility