Update: Oops, this wasn’t the problem at all. It was actually with the Content Permissions module. Forgot the site was using it! Pretty embarrassing
I just went through quite a struggle getting my CCK fields to appear on my Display Suite-managed node. I finally succeeded, though, in the end, and thought I would share the solution.
Don’t worry, there isn’t much to read: just disable and re-enable the Node Displays CCK (nd_cck) module found within in the Node Displays Contributions module.
I initially tried disabling and re-enabling all Display Suite-related modules, but that didn’t work. For some reason, however, disabling and re-enabling that specific one did.
Hope this solves someone’s problem!
(To read my full rant, check out this issue comment and the ones below.)