Changing joystick deadzone settings doesn't work?

[bugmenot]

I'm using a PS2 to PC adapter with Dolphin, and the left stick is a teeny bit loose. When playing games, the character will often automatically walk to the left even when I'm not pressing anything. I tried changing the dead zone settings in Dolphin, but even if I put 100% it doesn't affect anything at all. Does anyone have any idea what to do?