games don't work

Some of the games i have downloaded don't work and some can just be black or white or freeze. And when i gonna play a game i have a save file on it says, The file have corrupted. What is the problem? The games or my r4i? If it's my r4i, what can do to fix it?

You can copy your card contents onto your pc.Then download the latest firmware for you card.Format your card and install the firmware and copy your games back on also.

what's firmware?

Its files that your cart needs in order to play Romshttp://www.linfoxdomain.com/nintendo/ds/This is an example,you can go to the website listed on the box that your cart came in etc......

I downloaded the newest version, but does all games work good for you? If they do I can download same firmware as u got and then it might work.

I use an Acekard2i.Youll need to wait for someone that uses your cart to come along and advise to use original firmware or a better alternative.Someone on here did say that any cart with a letter,then a number is a load of crap anyway-but thats another story....

Well now i got an r4i and i wanna play games without lag and i wanna save and continue. Can someone help me? PLZ