Problem with Disgaea

I've recently downloaded Disgaea for the ds and it works fine, the problem is though that my save files get corrupted every time
In game it says save successful but when I try to access my save file it tells me that the data is corrupted and the save file deleted
I'm using a R4SDHC with patch 1.26 (dutch)
My other games seem to work as normal, it's just this one
Does anyone know how to solve this problem?

Read this thread.
https://www.romulation.org/forum/index.php?topic=1462.0:)

I've tried the arm7 stuff but it just messed up the game even more, now it doesn't play at all anymore instead of not saving..
other firmware didn't help either, tried the 1.28 version from linfox but it's still got the same problem.