NDS Games Corrupted save files

how come some of the games i played, after i save it and go back on it
it's becomes corrupt.Please help!

What games, what card?

Pokemon games
& the new r4... r4-III

Make sure you are using the latest firmware.
http://www.linfoxdomain.com/nintendo/ds/

so i download r4 III v.3.07?

I'm not sure. There are three different "R4 III" cards. Which one has the website from your box?

i found it, what if the pokemon save file still corrupted?

Replying to #7

Then you will have to look at arm7 patching your games.
https://www.romulation.org/forum/index.php?topic=1462.0