When editing a block and not having all faces of the block visible while editing this will create a block with some invisible / transparent faces.
It is annoying but can be fixed quite easily by just zooming out before closing the edit block command.
Should be fixed though 
Hi Morton - I am not seeing that yet here - can you give me a blow by blow of he steps?
-Pascal
Hi Pascal,
A. If i edit the block, zoom inside it and exit the editblock command some faces are invisible.
B. If i zoom out before exiting the editblock command everything is fine.
