I had the problem in uploading the multiple images.
Create a content type called "Photo slideshow" and add the field called images.
In the "Photoimage field settings" -> if I selected the "Unlimited" under "Number of values" field, I cant upload the single image.
If I change the "unlimited" to "1" then I can able to upload the image.
Note: This is the migrated website (6 to 7).
Please give a alternate solution for upload the multiple images with image caption.