Container fields on iMac versus Windows

[Bikeman17]

All buttons and icons are stored in the Interface layout in container fields. Then they are used in other layouts. In my iMac, they all appear with smooth and transparent corners. When I move the databases on Windows 7, I end up with white edges. Rectangle buttons were created with FileMaker tools and then pasted in the container fields. If I paste any buttons in a layout, they look fine. Where is the catch?

 

Please advise