Ibanez SR370M ... my old workhorse. Seemed to happen during a string change, but more likely I just didn't notice it before. Cuz I changed the D string and it's still muffled. It's muffled noticeable when unplugged so it's not a pickup issue. I've played with the saddle height ... nada. Soooo .... Where to look next? The nut doesn't appear cracked and the bridge looks ok. I'm gonna change the saddle on the bridge maybe this weekend. Thought I'd buy a few nut blanks and dust off my files. But I'm still curious what may be causing it. Very weird.