I have a R4-SDHC 3DS (the one before the 4.5 and 5.0)
In the update screen it says "NDS, NDSI:1.45, 3DS 5.0" and has the bomberman logo which it has had for a long time now, which suggests it works on the DSi, i have a DSi XL with 1.4.5E and the flashcart doesn't work at all load up the cart...