Scroll Ball Won't Activate Dashboard

I can still scroll just fine, but for some reason clicking the scroll ball no longer brings up the dashboard. I'm wondering if it's not just a setting that was inadvertently changed.

Right now, F4 is feeling miles away.

From the sound of it, you're using a Mighty Mouse...are you?

If so, make sure that the keyboard/mouse shortcuts inside the Exposé/Dashboard preferences didn't get inadvertently changed. Even if everything looks ok, CHANGE it to something else, save it, then come back and change it back to how you like it. Doing this can sometimes trigger the system into changing a 'stuck' preference.

The other possibility is there may be failing sensors inside the mighty mouse. If the above fix doesn't work, and the mighty mouse is still less than a year old, make an appointment at a Genius Bar to get it replaced or fixed.