The Newest kernel version of R4 Ultra is V1.55 (R4i Ultra and R4 Ultra use the same kernel), released in Oct.20 2009. If you have not known how to use R4 Ultra and the kernel package, please chick here to get the R4 Ultra guide.

R4i Ultra and R4 Ultra Kernel:

R4i Ultra and R4 Ultra Kernel Version: 1.55, English

R4i Ultra and R4 Ultra Kernel Version: 1.55, French

R4i Ultra Update file for Support DSi V1.4

R4ifw_update_14_DSi.nds (Pls install both V1.55 and this updation at the same time)
Notice: R4i Ultra Firmware Updation for DSi V1.4
>> Install lastest kernel and firmware r4ifw_update_14_dsi.nds, run the firmware firstly on your DS, DS Lite or DSi lower than version 1.4;
>> After updation completes, you can use R4i ultra on your DSi v1.4 now.

R4i Ultra Firmware updated file for Support European Language DSi System:
Flash_update_For_EUR.zip (Note: This Firmwar Updated file just for R4i Ultra, not for R4 Ultra, Run "ultrai_update.nds" on English System to reflash the chip of R4i, and don't power off when flashing.)