Problems Slicing

I have had a recent slicing Issue.

Z-Suite (Mac OS AND PC)

The component was incorrect sliced in the orientation I wanted to print, the rectangular hole was filled. I had to flip and re-slice to get the correct geometry. Please could someone see if they can re-create the problem? 

Image 1  incorrect slicing

Image 2 native stl

Image 3 correctly sliced after flipping component 

Original STL supplied with customer approval 

had flipping and re-slicing not worked, I would have had a real problem.... perhaps there is an intermittent feature recognition issue with z-suite? 

I have tried to report as a bug, but the files will not upload for some reason, so i am not able to report the problem. 

Thanks in advance


The model is badly designed, its not closed:

Fixed version attached.

ps. Dont afraid to use NetFabb or ;)