Nintendo only says that Acekard 2i DSi firmware update v1.4.1U "provides behind-the-scenes improvements to system performance," though Gamasutra notes that many--not all--brands of DSi emulator cards no longer work after the update is applied.
As with the DSi, Wii modding and hacking can allow users to run legitimate homebrew applications but also enables piracy.Nintendo's system menu update page says the new firmware.
provides "behind-the-scenes improvements", but as expected that is really just PR speak for "no more homebrew for you". This is the first incremental update for the DSi in over a year, yet it is not believed there are any new features for the DSi outside of flashcards being blocked.
As the subject title ,we have received quite a few similar question from DSi user .
We are sorry but have to say that we now didnt get any confirmed solution on how to upgrade the firmware from firmware v1.4.1 to v.14 .However, it is good news that there are several cards can work on DSi firmware v1.4.1 . as the r4i sdhc, r4i gold ,ackard 2i ect...
If you use a DSlite, put the file in your SD card which finished by : DSL.nds
Then, just run it.If you use a DSi, the firmware must be 1.4 or less. Then put the file in your SD card wich finisheb by : DSi.nds. Then just run it.