I occasionally see one or two icons in my Mac OS X 10.6 Snow Leopard dock show up as completely transparent. I can still click in that area to launch the application but that slot in the dock shows up empty.
I found a solution that brings the icons back (this could just be a temporary fix):
- Right-click the icon and choose Options – Show In Finder so that you can easily locate it in a future step.
- Drag the transparent icon away from the dock so that it turns into a puff of smoke.
- Open Applications – Utilities – Terminal then type “killall Dock” to restart the Dock
- From the window opened in step 1, drag the icon back into the dock where it was before