Mic has released yet another new version of his Nintendo DS Emulator for windows, heres whats new:

GPU: Fixed rendering of transparent areas on 256-color bitmap BGs
GPU: Fixed background color in the OpenGL renderer when luma effects are used
MMU: Added support for 64bit/32bit operations to the hardware divider
MMU: Fixed 32-bit reads from the IF register
MMU: Modified IRQ handling a bit

Download here --> http://nintendo-ds.dcemu.co.uk/dualis.shtml