Trouble with Rmagick and profile data

Rails
1

When I load up an image via rmagick, I get everything except profile
data:

(from script/console)

img = Magick::Image.read("/image_with_iptc.jpg").first
=> /image_with_iptc.jpg JPEG 2560x1600 2560x1600+0+0 DirectClass 8-bit
140kb

img.iptc_profile
=> nil

(This image definitely has an IPTC profile.)

Once loaded, I can add and edit IPTC data to an image, no problem. It
just won’t load the profile data already in the file.

Can anyone tell me how to troubleshoot this further?