As many a fellow caravaner knows the manufacturers do things on the cheap. Recently I had the gas strut screws detach themselves from the bed base, leaving insufficient material for the screws to be used again.
I solved the problem by replacing the screws with bolts, washers and nuts appropiate to the holes in the brackets. You need to drill holes right through the bed base wall.
I repeated the process on the other strut, eliminating any future trouble.