A method for controlling a fastener driving tool, said method comprising: (a) providing a fastener driving tool (10, 401) that includes: (i) a housing (24, 411), (ii) a system controller (50, 435), (iii) a fastener driving mechanism that moves a driver member (90, 490) toward an exit end (30, 417) of the mechanism, (iv) a safety contact element (32, 418), (v) a user-actuated trigger (54, 439), and (vi) a fastener; (b) said fastener driving tool further comprises: (vii) a prime mover (40, 427) that moves a lifter member (100, 400) which moves said driver member away from said exit end of the mechanism, and (viii) a latch control device (46, 431) that moves a latch member (120, 420) which has a catching surface (124, 424); (c) initiating a driving cycle by pressing said exit end against a workpiece and actuating said trigger, thereby: (i) causing said latch control device to activate, which moves said catching surface of the latch member to a position that does not interfere with movements of said driver member; and (ii) causing said fastener driving mechanism to force the driver member to move toward said exit end and drive said fastener into said workpiece; (d) actuating said prime mover, thereby moving said lifter member and causing said driver member to move away from said exit end toward a ready position; and (e) then de-activating said latch control device, which allows a mechanical biasing (144, 444) of said latch member to move the catching surface of the latch member to a position that interferes with movements of said driver member characterised in that: (f) said fastener driving mechanism includes a hollow cylinder (14, 405) with a movable piston (80, 458) therewithin, said piston being movable within said cylinder, said hollow cylinder containing a displacement volume (76, 457) created by a stroke of said piston; and (g) said tool includes a main storage chamber (74, 454, 774) that is in fluidic communication with said displacement volume of the cylinder, wherein said main storage chamber and said displacement volume are initially charged with a pressurized gas and remain above atmospheric pressue during all portions of an operating cycle with no gas replenishment system on-board said tool; and (h) during said driving cycle, said cylinder and piston acting as a gas spring (76, 457) to move said driver member from its ready position toward said exit end, using said pressurized gas of both said main storage chamber and said displacement volume acting on said piston. (a) providing a fastener driving tool (10, 401) that includes: (i) a housing (24, 411), (ii) a system controller (50, 435), (iii) a fastener driving mechanism that moves a driver member (90, 490) toward an exit end (30, 417) of the mechanism, (iv) a safety contact element (32, 418), (v) a user-actuated trigger (54, 439), and (vi) a fastener; (b) said fastener driving tool further comprises: (vii) a prime mover (40, 427) that moves a lifter member (100, 400) which moves said driver member away from said exit end of the mechanism, and (viii) a latch control device (46, 431) that moves a latch member (120, 420) which has a catching surface (124, 424); (c) initiating a driving cycle by pressing said exit end against a workpiece and actuating said trigger, thereby: (i) causing said latch control device to activate, which moves said catching surface of the latch member to a position that does not interfere with movements of said driver member; and (ii) causing said fastener driving mechanism to force the driver member to move toward said exit end and drive said fastener into said workpiece; (i) causing said latch control device to activate, which moves said catching surface of the latch member to a position that does not interfere with movements of said driver member; and (ii) causing said fastener driving mechanism to force the driver member to move toward said exit end and drive said fastener into said workpiece; (d) actuating said prime mover, thereby moving said lifter member and causing said driver member to move away from said exit end toward a ready position; and (e) then de-activating said latch control device, which allows a mechanical biasing (144, 444) of said latch member to move the catching surface of the latch member to a position that interferes with movements of said driver member characterised in that: (f) said fastener driving mechanism includes a hollow cylinder (14, 405) with a movable piston (80, 458) therewithin, said piston being movable within said cylinder, said hollow cylinder containing a displacement volume (76, 457) created by a stroke of said piston; and (g) said tool includes a main storage chamber (74, 454, 774) that is in fluidic communication with said displacement volume of the cylinder, wherein said main storage chamber and said displacement volume are initially charged with a pressurized gas and remain above atmospheric pressue during all portions of an operating cycle with no gas replenishment system on-board said tool; and (h) during said driving cycle, said cylinder and piston acting as a gas spring (76, 457) to move said driver member from its ready position toward said exit end, using said pressurized gas of both said main storage chamber and said displacement volume acting on said piston.