Glad you found the breaker. Sometimes they take the shortest run which may also be to a different floor or room. Hope you wrote down every room/receptacle/switch/light, etc. that goes with each breaker and put the sheet of paper by the main panel.
In regards to circuits mentioned in my post above, besides arcing at the point of the dead short, it will also arc easier at a place where there is a loose connection which could be a receptacle, switch, light, or even in a junction box in a wall or attic. A fire can start real fast and in a place where it may be too late to save your house before you catch it. Do some research on breakers, including gfci, and you will find they don't catch everything. The NEC being put together for 2002 is going to include an AFCI, which is an arc fault circuit interrupter, for places like the bedroom. Even gfci's aren't designed to hand direct shorts. There aren't many around yet and they get expensive but manufacturers are gearing up for them. Also, a short involving a neutral could also send current back on the neutral wire and energize other circuits attached at the panel or shared in between. Some circuits are sometimes wired with shared neutrals (such as the two kitchen appliance circuits using 3 wire with ground sheathed electrical cable) and with these circuits you would need to throw both breakers to be completely safe.
I just shorted out some christmas tree lights last week trying to adjust the tab in a socket and it sparked a half inch before it blew the automobile style round fuse inside the plug. It probably wasn't a good idea on my part to mention to a novice to change a switch or receptacle on a live circuit cause I have had a stiff wire slip on me and short out occasionally. Course I've built up some immunity (and probably warped my mind) from testing light sockets with my finger when I was a kid and testing batteries, such as 9 volt, by sticking them on my tongue, etc.