I bought a new Gibson 335 and the strings on it were lifeless. I replaced them with Fender Silverbullet 10s. I checked the intonation as follows: using a Korg tuner (the $20 model), I check the open E/6th string. It's good. I fret the 6th string at the 12th fret. Also good. I do the same for every string. They all check out fine. Only, chords don't sound too good. A barre G, for example. The 6th, 5th, and 4th strings are all sharp. Any ideas?