This is an outside possibility, but did you assemble your chain using a chain tool to push the rivet back in? The forces applied might have squeezed the chain's plates together at that link so close that they bind as they go around the chainrings/RD guide pulley's. Best indicator of this is if the chain 'jumps' a little bit every once in a while.

Also, if a square taper BB, check and make sure the pedal arms a properly seated on the square parts of the axle. If they are loose they will slip a little and make a repetitive clicking sound, and eventually come loose - reseat in arms, tap them on lightly with a mallet to make sure they are seated snugly, them screw in the lock bolt and torque it up to properly seat them.