Having some really odd issues with a 32G here too... brand new card. Phone sees it at boot.. and was fine moving most camera items to the SD.. except for the videos. At the videos, it crapped out.. says it is "blank" and needs formatting.. but then it can't format the disk, or access it at all. Reboot, seems fine. Disk is fine on other devices. Gives me a very uneasy feeling about the device.
Oh, and while its working.. if I delete a pic from the gallery, it keeps a dead, empty thumbnail there until I leave the gallery. Never pulled that BS with internal storage.