The flash requires at least Flash 8. Please get it here.
This text is stored in image.txt - in 1.6 you can store extra text for each image if you like here. But if you only want a caption you should simply login and anter the caption directly ;). Please read howto 28 for more details about image.txt!
That's a nice backside turn
Tip: If you login (right upper corner) you can enter captions, delete comments and rotate images permanently.