The S3 will supposedly accept an SDHC card up to 64GB. But, the SDHC standard only goes to 32GB. Anything over that is the SDXC standard. (See www.sdcard.org) So, my question is...is the S3 SDXC compliant?
I'm pretty sure the S3 has sdxc support, but it may not matter.
I'm running with a 64gb card in my Thunderbolt, which isn't sdxc compliant, with the full amount available. Just need to format the card to FAT32.
Format it in the phone. If you have sdxc support, it'll format to exFAT. If only sdhc, it'll format to FAT32.