Seen many posts saying similar issues...google it or browse xda forums....many formatted it to FAT on a PC and installed it with luck....but not all. Im guessing one of the upcoming updates may resolve this because its a known issue for some. I didnt bother reformatting and reinstalling because I dont really need it yet because Im still deciding if I will swap to a Electrify 2 due to continued cell signal issues. Thats the only upside to the E2 but critical in my specific area possibly.
I gotta say...USC stores and tech folks have been really outstanding in trying to resolve my issue. Its clearly a Samsung glitch with dropped calls and I think this SD issue also. Common sense tells me they will both be figured out and resolved with updates before long.....but that common sense thing is not always too common.
I just bought one on amazon for my xperia pro. The reviews says the 64gb is working on their s3.
Have you tried to reformat it on the phone itself or any android device? It fixed the card incompatibilty / not working on mine...
Read a thread that reformat on a pc is not ideal in this size. Android reformat is better.
I cannot reformat it as the S3 always removes it right away (dismounts) right after it detects there is a card there. So, it doesn't show up in storage for me to format it on the S3. I could format it on my laptop but I would need to know what format to use.
It will accept a 64gb. I read several posts where the phone didnt see it...thats why folks used a PC in those cases to reformat.
Several said they reformatted to FAT as I said...and had success. Your milage may vary. Let us know if it works or not.
I ran into the same issue with a 64GB Sandisk Ultra card. I could not get it to work in the phone at all even after reformatting. It is going back to the store and I will pick up a 32 GB that will work.