Power supply plug shield loose?

[Jack Countryman]

On the external power supply for a dual usb iBook or 12 inch PowerBook G4
(the square white one), the metal collar/shield on the plug that goes into
the computer has come loose.  If you try to pull the plug out of the
computer by the plug...the usual place to grab it...the shield comes off,
leaving the plug in the machine.

What was supposed to hold this in place?  There doesn¹t seem to be any
threads or other mechanical device...so these are glued on?  What sort of
glue?  Where should it be applied...only around the end of the collar where
it comes against the plug?

Thanks.