New SDHC Card acts strange on R4 SDHC. A little help?

I recently got a new Micro SD card, a 16GB Sandisk SDHC one, and decided to use it for my R4 SDHC. The problem is that some games have their bottom screen logo replaced with a generic one, and the icon for cheats is missing. I've also tried using the Lameboy on it, and it works fine but doesn't load any games, and the log simply states an "Unknown MBC". The strange thing is, everything works fine on my old SD card, 4GB Kingston SDHC. Does anybody know why my 16GB SD card work like the other one? I've already considered it was because of them being from two different companies, but that seems like it shouldn't matter.

Thanks a lot in advance.

 

well it could be that it is new and you have to use it a bit. or 2 try reformating. the same thing happen to me but i dont use the ar cheats so i am good

 

I'll try reformatting and see how that goes, thanks.

 

so how did it go did that work or does the ar codes still not work

 

I've had similar issues with my R4 sdhc
I bought a 8GB class 2 sandisk and it was slow and acting weird, kinda like how you describe it

so I switch to a faster 8GB class 6 micro sdhc and all the problems went away..but I can't say for sure if it was a micro sd problem or not because that 8gb class 2 sandisk works fine on my dstwo..

 

Well formatting it worked, i guess i had just never really gotten around to doing it in the first place. So thanks for all the help, ya'll have a good day now!