Originally Posted by nuno
i think a backbow would cause buzzing on more than 1 fret.
I think Rich really means there is not enough relief, not that it's bowed back.
On my RG520 if the neck doesn't have just the right "dip" to it, it will ONLY buzz at the 5th fret on the low E string.
It's a slightly low fret on my guitar, the other frets are good, I'm just too lazy to pull that ONE fret, re-seat it a little higher, level it again, dress it, blah blah blah, when the difference between .35 and .45 MM neck relief fixes it. :-)
That and most necks don't curve smoothly. If you read Rich's step by step cleaning and setup pages, the guitar he used for the pics has a slight back-bow in the lower positions, even with proper relief measured at about fret 8 or 9, so he had to use a little more relief than he normally would to compensate.
Now, none if this is saying you're wrong, mind you, but it's much easier, and faster/cheaper, to check neck relief first, THEN if that's not a quick fix, look at the frets themselves. :-)