I've got a Peavy Mantis that I've finally decided to learn properly after way too many years to mention. I've put on new strings and have tuned it up using an electronic tuner. Actually, two different electronic tuners say that all the strings are in tune. But, when I hit the low E string at the 5th fret - that should give me the A of the A string, right? It comes out WAY sharp and both tuners tell me it is very sharp. Any ideas? All the other 5th (or 4th) fret tuning steps seem to work fine.

-Kirk