I just got Prince of Persia: The Sands of Time from GOG.com, and I'm having a problem where all inputs are lagged, both keyboard and mouse. I've changed AA, AF, Catalyst A.I., and wait for V-sync, but the problem still persists. Compatibility mode and locking affinity to a single CPU core don't help. What should I do?
Windows 7, ATI Mobility Radeon HD 5650, AMD Phenom II 2.0 GHz quad core, 8GB memory.