For Chirstmas, my dad got me an Ibanez Stagestar p-bass. It's been working nicely so far, but I can't set the intonation on it. Turning the screws either way on the back of the bridge don't move the saddles at all. I'm including some pictures of a similar bridge to give you an idea of what its like, but this isn't actually my bass. Sorry about the quality, but I don't have a working digital camera and this is the best I could find online. Is my bridge just screwed up, or am I doing this wrong? I'd like to avoid paying to have it set up if I can.