Mac Dock not doing the "zoom thing"

Every once in a while I've noticed on our iMac that the dock highlighting stops working. The first icon you mouse over zooms up but it doesn't change if you move over other icons.

I've been Googling for an answer, and it took the right combination of keywords ("imac dock not highlighting") to find this thread on MacRumors.com.

In the first post, a person reports exactly what I'm experiencing. People replied with the usual suggestions: Reboot, Repair Permissions, Reinstall Updates, etc.

On the last post I found this comment:

Hi, I had the same problem but in Leopard. All mouse over effects spontaneously disappeared and stayed off even through reboots.

Once I unplugged and re-plugged my mouse, everything worked fine again.

I suppose if you're on a laptop then plugging in an external mouse might help.

Hope this helps!

I gave it a shot and it worked! I hadn't noticed, but now that I think of it, mouse-over highlighting in general seems to be not right. Hopefully by blogging this, other people will find this solution easier.