In the "Unwrapping the Treads" video Jonathan snaps edge loops of one island to the vertices of another island in the UV map:
When I have the snap tool turned on and set to vertices (not increments), this is what happens:
I've tried it in vertex, edge, and face mode and experimented with other things too. What am I doing wrong? My file's here if needed: http://pasteall.org/blend/index.php?id=52502
Thanks for your help!