If you do more than one weight it will wipe out the data from the previous weigh in, I had read before that Garmin is looking into allowing more than one.....I think.
Time to send a reminder again. This weight is a disaster, not only allow 1 reading pr. day, but do not have the capability to see the differens between me and my wife (43Kg different) So for me it`s another garminproject, and they don`t seem to do something with it either.
It is now possible to weigh in several times per day and have Garmin Connect - the infrastructure holding the data - both store and present the data. Available from around a week back.