When I tune my guitar (with an electronic tuner, some times check with the organ) and it is in tune - then when I play it doesn't sound quite right. Checking with the tuner; for instance, the C on the B string, the note is sharp, while the B is in tune. Anybody know what causes this?

I also find my guitar easier to play with the capo on - the strings are closer to the fretboard then - do the better quality guitars have the strings situated closer to the fretboard? Is that why they are said to be easier to play?