focusedWindow() results in inconsistent and wrong coordinates

Basically what title says. When the actual location was x = 410 and y = 182, it returned x = 513 and y = 227. It also got the width and the length wrong. If it was consistent with how much of x and how much of y it was offset by, I would just offset it back, but it's not consistent with that either. I've seen errors of anywhere from 30 to 300 pixels. Is there a fix to this, or is this a problem on my side?