Originally Posted by BlastRadius
Don't run the "2007 SHIMANO 105 FD-5600-B Front Derailleur" with the 9-speed chain. The spacing between the plates is narrower on the 10-speed FDs and you won't be able to get the shifting as good as it should be.
Yeah, I've learned that "10 speed" implies much more than the number of gears in back. I took my a while to understand why cranksets were designated "10 speed" - it's the external BB cups and fixed spindle on the drive side crank.