This is a common problem in our hobby, and the "super glue" solution
is very good, although with small screws I also find the old trick,
"glue a toothpick in the hole", also works.  I understand Luke's lament
about bad screw holes, but I think screwed-on pneumatics are much
easier to repair than glued-on ones that don't like to be taken off
(although Simplex style pneumatics are also no fun to replace pouches
and valves because they have to be split apart).

One does have to learn how to "feel" when the screw is going into the
old threads and not making new ones.  There are lots of little "tricks"
to learn when restoring our beloved instruments, and each job usually
teaches us one more thing we hadn't noticed before!

David Dewey