I have a 3/4 sized acoustic and just noticed that the wrapping on my D string at the 5th fret has broken and is unwinding - the string itself has not snapped totally, yet. I also noticed that there is a notch worn into the fret directly underneath the exposed string where it is coming unwound.

Which do you think is most likely to have caused which? The fret got a notch in and has broken the string or the string broke and caused the notch?

And perhaps more importantly - how do I fix it (the notch)? It buzzes horribly...

Thanks in advance

Replace the string

That happens to me sometimes, it's easily fixed by just replacing the damn thing

Oh yeah, replace the fret too if it's too worn

How long has it been since you replaced the string?
the exact same thing happened twice on my 3/4 acoustic, but never on the full size. you just use that note too much. get the string and fret replaced also
I replaced all the strings last week. She's an SX Baby, which is a copy of a Baby Taylor. I bought her for $100 on eBay two years ago and she's been everywhere with me. Although I love her I'm not sure that replacing the fret is worthwhile. I though that would be expensive?
Frets wear from normal use. Strings are also softer material than the frets, so they get the windings worn off if you use them long enough.

Also, if you leave a capo on, fretting the guitar, it'll make it wear really quickly.
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Frets are east to replace usually. only problem is lifting it up without damaging the fretboard. think of it as a rounded arrowhead. the fret sits out and against the wood with the neck behind it. it usually wont be glued in, just a snug fit.

I'd reccomend you ask them to fix it but let you watch to see how its done, or you could not worry and just give it to them. but I wouldnt go straight in with a letter opener without a bit of at least reading.
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