TTDSi does not work

Hi I have a problem, I borrowed my sister my DSi and she updated my DSi to the latest version.
Now my TTDSi card doesn't work anymore every time I try to use it I get an error message.
So here is my question: can I downgrade my DSi or do I have to buy a new flashcard which works with the latest DSi firmware?

it is not possible to downgrade the DSi.

The TTDSi hasn't been updated in a while, so I doubt it would support the DSi 1.4.4 firmware.
You will have to by a new card that supports it.You could choose:- Acekard 2i
- R4i Gold 3DS (r4ids.cn)
- Supercard DSTwoGo onto www.shoptemp.net to see some good prices and comparations.