Gary Gifford wrote on Fri, May 12, 2006 06:51 PM EDT:
The 50 move rule is a bit more than what was recently stated regarding pawn
movement. The rule makes the game drawn, if
the last 50 consecutive moves have been made without the movement of any
pawn AND without the capture of any piece (or pawn).
Thus,when a piece is captured (or a pawn) the 50 move count must start all
over again.