If you're using GW, don't you want to try out the 2.5.2 version of rx? (different rxTools.dat, and firmware.bin - 943K).But my emunand works perfectly, I can play any cia games if this i what you're asking :x
(And i've installed the devmenu with PBT-CFW)
If you're now playing with rx, that's a milestone for your effort.
What 2.6 offers includes region-free (only cia, and cia manual would break) and AGB(tricky iirc).
Well hope those solve your problem. (Don't ask me about AGB, I only play DS ones with the cart or 3DS ones on my console with rx).