I have a PB 1400 that is prone to this, and the cause on that machine is a crimped screen cable. Try gently flexing the display to max tilt for the hinge, then come back towards perpendicular from the keyboard. You may find the problem relieves itself. I always have to remind myself when this one unit does it that that is the cause. Good luck, worth a shot. The 2300 is a great little PB.