Ace kard

Hello, I got the ace kard it came with a sandisk reader and with a 8 gb minisd card. it worked then when i put the foruth game and tryed it out in my dsi it didn't work. i try installing the acekard thing again but nothing happen and my computer won't read it eaither. but i had two same card but 128 mb and it's annoying that it only can hold 1 game in each so help me fix the 8gb plez.