I'm seeing strange partial iOS-style "close" buttons when I hover over the area where Notification Center alerts appear. It seems there is one created per notification shown, which means over the course of a day there is enough to fill 3 columns of my screen.
- They only appear when my external monitor is plugged in (I use it as the primary display)
- The buttons slide away when I use "show desktop" (command + F3)
- Unplugging and reconnecting the external display resets the ghost notifications, and they start appearing again as new notifications arrive.
- The partial button only fades in when I mouse over the hoverable area, which is quite slim, but as wide as a notification.
- Clicking the close button has the expected behaviour on mousedown (looks depressed) and after click (fades out, doesn't reappear on subsequent mouse over)
Is anyone aware of this issue, if/how to file a bug with Apple or if there's any workaround?
Running OS X 10.8.2 on a MacBookPro9,2