thanks vejesse.....by writing these replies i kind of got to thinking and cured the problem.
ok its a three point gibson bridge but the rear two are below the front one ..thus causing and upward pulling moment about the front point ..thus dragging the ferrules out of the body.
by raising the rear screws to the level of the front screw point in the same vector as the strings the upward force was reduced to zero but made very little difference to the action!!
never had one of these type of bridges before but now it seems so obvious.
