Hi All,
I think Marcus is right that the two (four?) little magnets in the box are small enough that they are not likely to cause a problem, but certainly if you put them right up against the watch it would cause it to go funny in short order. I've told this anecdote several times already but it bears repeating I think: A friend left a watch with anti-magnetic shielding laying down on a cell phone case with a magnetic closure over night (or at least for a few hours) and it caused it to run +30 s/d. After demagnetizing it was back to +1 s/d. Nivarox is only marginally resistant to magnetism and most anti-magnetic shielding is only marginally effective on top of that. Still, tiny magnets at a distance of more than a couple inches is not gonna magnetize your watch.
_john