Ken and I were talking about the origin of the word discombobulated yesterday. "dis" and "com" are combining forms in English, but there's certainly no root verb bobulate or combobulate.
Random House, American Heritage, and Webster all have it as an American coinage with dates varying from 1825 to 1916. Supposedly a fanciful play on the word "discomfort" or "discompose". Other variants show up, too: discombobricate, discombobberate, or a recent variant discomboobulate.
But there's a wholely different theory which I first found on a MySpace profile, that discombobulate is connected to the Italian word scombussolare. That Italian verb has roughly the same meaning as discombobulate and is derived from the word bussola, compass, as in "lose one's compass bearing". Supposedly scombussolare is a 17th centuary Italian word, but alas I don't have any more authoritative reference than a forum thread. And how do we get to discombobulate with the extra negative prefix?
There's something sinful about pretending to do this kind of research solely on the Internet, when all the relevant sources are over a hundred years old.