Over tightening or removing wood screws too many times can cause stripped wood problems. Removing cupboard doors for repainting etc. can cause the wood to fall away and therefore the wood screw has nothing to hold onto.
A quick and sure way to deal with this problem is probably already in your cupboard. Take some round tooth picks, place one at a time into the screw hole and break it off level with the surface, continue until the hole is full. The last one with a pointed end, tap it in with a hammer, break it off, put the screw back in place and you are done! Although no glue is required, in some really bad situations add the glue.
Screws that are stripped will not screw out in a normal fashion. To remove a badly stripped screw, you will have to help, by applying a slight outward pressure while un-screwing. Insert a chisel or screwdriver behind the hinge, bracket, etc and gently pry outward while un-screwing (this technique can be used to remove stripped metal bolts also)
Repairing Stripped Metal Screw Holes
If the threads are only slightly stripped you can usually repair them by running a threading tap of the right size and thread pitch, through the damaged threads. If the threads are excessfully damaged the only course left, is to drill the hole to the next size up and retap to the larger size.