Hi Gman,
On more than one occasion I have known the guitar strap to become
unhooked.
I now make a 'washer' from an old credit card or similar. The
washer is 3cm in diameter
(1.2") with a hole in the middle slightly smaller than the strap
peg.
To make it easier to fit, the washer can be cut. The washer
then fits on top of the strap and prevents it from coming off.
Regards,
Steve Nicholls