The intonation on the b string of my strat is out, its too low, I know you're supposed to bring the bridge saddle towards the neck but I've moved it as far as it goes and its still out, I've even tried sticking cardboard between the string and the saddle but nothings working what should I do?
1. Is this the first time you've intonated this guitar?

2. Is it just the B string that is giving you issues?

3. Are these new strings or old?

4. What gauge are they, and if new, is it the same as the old?

5. Are you muting the other strings to make sure you're not getting odd harmonics from them that would cause the tuner to be inaccurate?