Wierd R4 problem

I have 2 memory cards, one made by Toshiba, and the other made by ScanDisk. The Toshiba one was the main one I used and I started to notice some games not working even on the latest firmware (white screens when launched), and now it has happened to them all. So I changed my memory card to my ScanDisk one and set that card up with the latest firmware and everything, worked fine until something happened with DSOrganise and it got currupted and I can't seem to launch my games again, well some of them launch but after the title screen go black or white.Is this problem because of DSOrganise? Or with my R4? Or with my micro SD card. Ive tried reformatting in FAT and FAT32 but it still doesnt work. :-[

Well Kingston and SANDISK are the best MicroSD brands, so there shouldn't be a problem with it. Try redownloading DSOrganize. That seems to work in most cases. Also, what games don't work?