After a recent string change, I'm finding that when I play a note from about the 7th fret onwards on my E-string the vibration of the string is catching the fretboard further down towards the 15th fret, making a nasty clacking noise and choking the notes a bit.  It gets worse the harder I play, and if I detune the string to D, which I need to for a song. 
 
The action seems reasonable - it's certainly not perilously low.  Is this symptomatic of a lack of relief or too much relief in the neck, and is a tweak of the truss rod likely to solve it?