Running 10.7.4 on a macbook 2,1 (white polycarb), I realised I couldn't left/right click parts of the screen: I tested different apps, tried safe mode and killing different processes, reset the SMC & PRAM but eventually spotted that I could always click the dock, and the unresponsive portion of the screen always depended on where the (3D) dock was positioned.
TL,DR: I'd customised my dock using CandyBar; reset my dock to defaults and all was back to normal.
Spent ages trying to fix this, hope this helps out someone else.
TL,DR: I'd customised my dock using CandyBar; reset my dock to defaults and all was back to normal.
Spent ages trying to fix this, hope this helps out someone else.