Next time you change your strings, take a towel, and whipe it down... I'm a Nazi with keeping my guitar clean, I whipe smudges off every night and if there is anything under the fretboard, I take the strings off, and then clean it, and then I put them back in (that really helps with my lack of feeling the need to tune it).
Practice the song slowly at first until you have it completely perfect, then try faster.