I have used my 970 to race a previous activity 3 times. Yesterday I raced a previous activity from history and in the space of 500m I seemingly gained about 3 mins. Today I was 32s ahead. I happened to glance at the watch about only 20m later and noticed that I was 51s ahead. From then on it seemed to reflect how far ahead I was except that it was showing 19s more ahead than was true. I have had similar problems with previous Garmin watches such as the 245 and 265. I reported this to Garmin when I used previous watches but they were unable to fix it. Am I just unlucky in repeatedly buying watches that happen to be faulty or is there some underlying problem with the software. I'd appreciate feedback from others who have tried racing a previous activity.