Update: I have not forgotten about this. The development changes are more or less done but one part is not working well so I need a few more days as I am juggling this and my day job. Sorry.
As many of you have noticed, TrendWeight is not working with Withings/Nokia scales at the moment. Withings changed their API this week and I will have to update TrendWeight to conform to the new requirements. It's not a massive change, and it essentially makes Withings match what FitBit already does.
Unfortunatly, I am currently out of town and without a real computer with which to make those changes. I should be home sometime next week and will work on the changes as quickly as I can. Until then, thank you for your patience.
Go ahead and keep weighing yourself every day. When the changes are complete, you're missing weights will all show up.