Hacking R4i - Is it safe to update the DSi firmware to 1.4.5?

[apoptygma]

I've got a DSi here with 1.4.1 A firmware and it's running this cart http://r4i-sdhc.com/downloade.asp (the top one, with the 3DS logo)
And I've just updated the software on the cart to 1.81b
Will it work with 1.4.5 firmware on the console?

 

[apoptygma]

From what I can tell I should be oaky once I update the cart, but i'm not able to do that, it seems to be stuck on 1.5. If i put the update on the sd and then click update it just shows the current version. In the config it has upgrade 'on' and the file is there (flash.r4i)

 

[apoptygma]

*bump*