Intoning a strat - now it buzzes!

[Elliot]

I was getting the intonation right on my Mex Classic 60s strat today - and two problems emerged - 1. their is not enough screw on the bottom E to get the intonation perfect - indeed it stays flat by 10 cents whatever I do.  Could be that the nut is chipped on the bottom E after a fall?   2.  The rest of the strings are now right but the middle strings buzz like a git after the 3rd fret.  This guitar never had any buzzes before. 

I suppose the easy answer is to raise the action, but what is the diagnosis?? 

[Supernaught]

Firstly I assume youre using fresh strings?   Theres no point intonating with anything else.

Secondly, it might be worth checking your trussrod before changing the action.   If youve moved the saddles forwards there'd be a very small reduction in tension.   Id be very suprised if it would be enough to change the neck relief but its worth checking before changing the action.

If youve not seen it before Ive always sworn by this:  http://www.fender.co.uk/support/stratocaster.php

Good luck  :)

[Ratrod]

Take it to a good tech for a pro setup.

Seems like you have a problem with the nut, action and neck curvature.

[FELINEGUITARS]

Sounds like a possiblle truss rod or height adjustment issue
You are welcome to pop in and have me look it over