In article ,
says...
Any ideas?

For ages I've been glueing small plugs in with foaming polyurethane glue
[1]. Moisten the hole somehow (outdoors I use a water pistol!) and then
dip the plug in the glue and shove it in the hole. Works a treat.

If you're on a posh surface, lightly press a strip of masking tape
downwards for a few inches under the hole just in case it dribbles.

[1] http://www.screwfix.com/prods/44485/Sealants-
Adhesives/Adhesives/Wood-Glues/Polyurethane-Adhesive/Joiners-Mate-
Adhesive-500ml
because I happened to have half a bottle left over from a job.

--
Skipweasel.
Never knowingly understood.