(sorry this is a few weeks late but...) I've had to fix several aging laptops with this problem and my out of warrantee Sager is no exception (although it has really held up well, considering). I reinforce my hinge areas on the case with fiberglass: I take the monitor out of the case (carefully - there are guides on the 'net about how to get the monitor out - be sure to unplug the computer and remove the battery too, and protect the inverter inside the case with tape or wax-paper), then carefully glue the area together with CA/Super-Glue and flex the parts together to make a clean fix. While it's apart scuff a several-inch-square area up around the hinge area on the case where the hinge screws to it, and clean with alcohol. Once that's done cut a 2-3 inch square piece of fiberglass cloth and lay it right up to where the screws tap into the case but keep it smooth without bunching up too much or it the monitor won't fit properly later. Lay up the fiberglass with either resin, epoxy, or CA/Super-Glue, use a small squeegee or piece of wax-paper to push the glue into the cloth and smooth it down. Reassmble the monitor after the 'glass is completely dry.
The fiberglass fix/mod spreads the loads from the hinges across a wider area and beefs-up the mounting points. It isn't a permanent fix, but it helps, and has added a few years to the laptops I've had.
