If you move into range 1 of a mine during the deployment step via the Scout keyword, does it detonate? Can you start losing dudes before the first round even begins?

Since Minefield specifies it is triggered when a non-repulsor unit performs a move, and is at Range 1 and in LoS of a token it might detonate and a Scout X move is a move (but not a move action) then I would say that it most definitely triggers due to a Scout move in deployment

That's how we read it. That's how we played it too. Lost two men before the game really even started.

I get the feeling that Minefield isn't played that often. I like the idea of it, only played it once on a 3'x3'and the red dice didn't like me that day.