A:
If you are taking large images, they may fill up a smaller TD like yours too quickly. Remember, many modern cameras are able to take up to 25 MB images.
Too, if you have other non-essential stuff already on the TD, like games and videos, or additional images, you may have severely limited the total available space on the TD. It doesn't offer you the entire 32GB to begin with since some of the space is used for the operating program.