It used to be very complicated/trouble for people to make their Ak2i to be compatible with the DSi and DSi XL (1.4 firmware and above) ,Since You will need a regular Nintendo DS or DS Lite to perform this update . Finally , there is a new version supporting 1.4.1 directly comes out .

Lightake.com are offering this Acekard 2i for $12.99 + free shipping .