thanks for the info. the strings are brand new. poshphor bronz. it may have been moisture that has made its way into the wood. i didnt touch the guitar for a month. but i do recall when my ninth fret all the way to the 20th fret sounded like the same note-so what i did was take a flathead scewdriver and pushed some of the fret bars ( 9-20 ) up and pushed them back into they're original places and the frets sounded as they did before all that one note mess. but when i try to do the same thing to the 12th fret bar it doesent change a thing.....maby its time for a new guitar....