About 300-400 miles ago I installed a new Shimano 105 (FC-5603?) 10spd triple crankset on my LeMond. I noticed in the last couple days there's a faint intermittent "click". It's definitely related to crank rotation, when coasting there's no noise. I've experienced my share of square taper BB issues over the years and this neither sounded like that, nor clearly occurred at a specific crank orientation.
This weekend I might remove the crank and give the BB cups an extra tightening - but this does not sound like the notorious pop/click heard when the drive side arm is at high noon. I have worn out external BB bearings on a different crank, and this is not that distinct of a noise.
I've read sheldon's cheat sheet for narrowing noises and this is too subtle for me to nail down.