3.5" floppy failure mode? Hub not attched to media.

[John Foust]

While reading old Amiga floppies with the SuperCard Pro, I have
encountered several floppies where it seems the mag-media cookie
is no longer attached to the metal hub.  

I first saw this when I tried to clean the cookie with a swab
of isopropyl.  I'd turn the hub but the media wouldn't turn.

Any advice on repairing this?  A spot of superglue?

- John