[Ashlandchris]

depends how critical the part is (i.e. how much stress is it under?)

There are a few fixes I have used: -

a thin rubber band fed into the hole and then the screw retightened - the rubber allows the screw to bite and gives friction.
Likewise, sometimes a match or sliver of a match can do the same.
I've tried a small cable tie fed into the hole, but often the nylon doesn't "lock" as well when screwed against.

or superglue...