Toptoy gold dsi

I've just bought a gold tt dsi card, but when i try using it it loads up first time, goes to game screen but as soon as i choose a game it gives an error message saying ttmenu error restart dsi. when i do i find that its renamed the files on the sd card and wont start up again. is there anyway around this? i think the dsi is running 1.4E is that like the wii firmware that stopped homebrew etc?

Make sure your cards are formatted properly
Try them in other devices to make sure they work