thats weird, my 360 controller works fine. maybe try unplugging it then pluggin it back in or maybe reboot your computer, that seems to fix most probs XD
about ur cpu, maybe u have background programs running which are takin up some cpu power (my logitech g19 lcd screen takes about 100mhz of my cpu and about 200mb ram, my steam takes abit as well). the game only puts my amd athlon x2 dual core 3.2ghz to about 20% on the first core and 10% on my second core. i managed to have 28 pso game clients running until my computer shut itself down to stop itself over-heating LOL (btw if any kiddies are reading this then dont try this at home, ur computer might blow our house up! XD)
sorry i couldnt help much but good luck!