Until I updated my S2 to 4.2.3 the HRM was working fine and agreed generally with my Polar heart rate chest strap. Since updating to 4.2.3 the HRM in my AW seems to be quite inconsistent, normally running lower than what the strap shows and what I would expect, and "bouncing around" a bit. Anybody else having this problem? Any suggestions? I've rebooted everything. Thanks.