Major Jump Glitch in Wii Heart Rate Monitor

I have just finished workout 9 on the 9 WEEK PROGRAM using a Wii and WiFi connection. For the third time a major incorrect reading has been detected by the heart monitor. A steady increase in rate was detected correctly between 113 and 118 BPM on two exercises, but between these two it shot up to 179 on 'Your Last Workout Summary"! But even this figure does not tally with 'Max Heart Rate' in Tracker which reports 190BPM. Is anybody else having this problem, albeit, minor? Are you aware of it and able to explain it, EA? I actually check and monitor the arm HRM every workout using a Garmin Chest HRM and sports watch, which I also record, and mostly they are in reasonable agreement, accept for this major jump in heart rate which the Garmin never picks up!