First, it seems to never stop until you turn the switch to 'off'. 

Second, and this is weird, when OS engages, it bumps the focus up. Seriously, it's like something will come from under your focused image and just bump the focus so that it shifts upward. 

Fortunately the lens is just fine when you leave OS in the off position. Basically it's a newer version on the non-OS lens, and it has a tripod collar.

See my other Nikon ads. Thanks!