Thanks.....it wasn't clear in the manual where to index it. Its hard to see the line on a black sensor (I didn't even know there was an index line until the diagram). I'm not sure who assembled the magnet in that spot but its a poor choice - there's no way it could be positioned properly given that the reflector is mounted right where it needs to be. Easily fixed.
I was just giving you some friendly technical smack on your tsk... tsk... for the Germans not designing LED feedback. Garmin does have feedback and my sensor last about 1.5-2 months (when used often) before it needs another 2032 cell, so tusk...tusk... to your tsk...tsk and that design as well.