EVERY single guitar i've owned has had terrible intonation.

My friend's dad's casino that I borrowed is still a bit sharp on the g string, but to the untrained ear, (not say I'm all that well-trained), it's unnoticeable.

However, I own an Epiphone Custom Les Paul.

I love me some octaves, so I play them up and down the fretboard, almost always with the A and G.

As I move past the 12 fret, it becomes more and more obvious that the intonation is out. I've checked using the 12 fret harmonic/12th fret technique, and I've tried adjusting it properly and to no avail.

The saddles have been moved as far as they can be, and I've even reversed the bridge in order to achieve a greater range of adjustment.

Any ideas? Could it be the strings?
I'm using Ernie Ball 9s.
Check that your neck isn't bowing and that your frets aren't terribly worn. Also make sure you aren't using too much force on the strings as 9's can be easily pressed sharp.
Quote by Altered_Carbon
That's some bony hipster sex, which may be the best kind.
Well, the other issue might jsut be the fact that you are playiing 9's. I have never had good intonation with themm, esp if you have jumbo frets. It might be that you are just holding the strings down to hard.
Main Rigs
Thineline tele with SD lil '59

Ibanez Artcore AM-73

Line 6 Variax 500


Line 6 X3 live
Digitech RP-500
Ibanez Weeping Demon

Roland JC-120
Rocktron VT-60
I'm having the EXACT same problem, man. I got some new Sperzel tuners put on a while ago, and I had some 9's...It was good. Then I put my .10 DR's on, and dear jesus...Just the A string, though. Harmonically, it's great. Fretted, it's about 20 points sharp. And the dude at the music place said "testing it harmonically is the only real way to see if it's intonated" Doesn't do me much good, when I'm trying to fret things past the 12th, eh? Jesus...

Anyway, I dunno what it is yet, man. It may be a bad batch of strings, could be anything.

EDIT: Actually, do you know if the saddle is even moving? Cause I think mine may be stripped.
My gear:
Schecter C-1+ w/ Seymour duncan Jazz (neck) and Full Shred (bridge), with Sperzels
B-52 LG-100A 4x12 half stack
Rogue LX405 Bass
Yamaha classical
Some sort of acoustic Squier
Boss Flanger
Lyon Chorus
Well I've seen the saddle move physically when I adjusted it so I'm sure it moves.

Perhaps it is like the others said and just a mere truss rod or string weight problem.