I managed to get one of my favourite DS games working in Loadiine v4, Hotel Dusk Room 215, using the rom.zip version of Brain Training that's floating around.
It has some graphical glitches during certain scenes (the bottom screen displays a garbage frame from the graphics on the top screen every so often), but it's nothing game-breaking.
Edit: It's unplayable, sadly. Clicking on objects does nothing, so you can't investigate. Bummer.
Off-topic thought: It'd be nice if we could inject into alldata.bin for GBA games (assuming the ROM is in there), or is that a matter of editing the rpx file (rpx -> elf -> look for ROM, replace -> back to rpx), so that it works in Loadiine?