I was changing strings on my 2005 Les Paul Standard and was using that opportunity to tweak the action. I had recently installed a Tone Pros Tunematic bridge which employs set screws to secure the bridge level. I loosened the set screws, strung up my guitar, tweaked, the height - a little here and a little there -- but when I went to tighten the set screws, one was missing. I had loosened it too much and it fell out on to the carpet floor. I spent the next 30 minutes on my knees with a flashlight and a magnet but it was nowhere to be found. Guitar Repair Parts came to my rescue -- they had the set screws, the price was reasonable, and the shipping speedy. Crisis averted. Incidentally, a week later while I was playing my LP, I noticed the old set screw sitting in the carpet shining like the Holy Grail. Go figure!