Mouse Wheel bubble up

Are you somehow actively preventing the onmousewheel event from bubbling up to the containing window? I'm trying to implement a (much, much simpler) grid control and moving the mouse wheel over the DIV causes the entire window to scroll. Even when I use "overflow=auto", the window scrolls once I reach the bottom of the DIV, but your wonderful grid doesn't seem to have this problem. Any hints?

Thanks!