Deconstruction of paintings does not return the fiber used

I've encountered what I believe to be a bug.  

I covered my base with paintings, using up a LOT of fiber, and then when the artist was sufficiently trained, I went to deconstruct them all to rebuild them. 

The paintings were deconstructed, and *appeared* to drop the fiber back (graphically). 

But when I went to make more paintings, the fibers didn't count as available and disappeared as soon as the dupes tried to move them into storage.