Hello! I'm new here -- and looking for some suggestions on a drywall dilemma. The drywall that our central air vent screws in to has crumbled. Not the entire area of drywall -- just the small areas on the left & right sides where the vent screws into the wall. This has never happened to us before and we have no idea what would be the best way to fix it. Any comments/suggestions are welcome. Thanks a bunch!