IDEA 12.x dancing toolbar on Mac OS

An annoyance I've experienced since upgrading to 12.x is that the main toolbar icons shift position when the mouse pointer hovers over them. Any slight movement of the mouse over the icon causes it to move, making selecting the icon difficult. I've seen this behavior on my iMac desktop and my MacBook laptop.  

IDEA:  12.0, 12.1
MAC OS: 10.8.2

Anyone else out there having this problem?

thanks,
Pat