When I import data from my S710, the total of all lap climbs exceeds the climb shown in the main window. For example:
Lap climbs: 40 60 265 125 95 30 155 0 (total 770)
Overall climb: 740
At first, I assumed this was because of rounding. But if lap climbs rounded to the closest 5 feet, the maximum discrepancy would be 2.5x7 = 17.5 feet, much less than 30 feet. So I would guess the numbers are all rounded up.