DSTTi - this does work but has a comment that it does not have an upgradeable Kernal - so it may be made useless by a firmware upgrade on the DSi (this is a comment by the manufacturer!)
R4i - too many to mention - avoid like the plague!
A firmware upgrade will be looking at blocking all of these types of cards because of there capability, dstt is the only one that advices you of this though. what ever rom cart you using i would not upgrade or the cart may become useless regardless of the make of card. better safe than sorry
There are two parts to the software on the DSi (and DSL) carts
The Kernal software - this is the firmware already in the cart, without even having an SD card inserted the cart has some function, telling you there is no SD inserted - incorrect firmware, logo etc
The firmware - the part that is upgraded to improve game compatability, this is on the SD card.
The Kernal on several carts AceKart (has already had a Kernal update), EZ Flash, DS Onei can be upgraded, this will allow them to change the function on the cart if the DSi upgrade makes the cart no longer function.
DSTTi does not have this function - R4i do not either - That is why if you are purchasing now the others are a better bet.
The AceKart update was to allow the cart to function in a DSi with the language set to anything other than English, it came as an NDS file that had to be run then removed from the cart.
