Hi John,
I understand your irritation. Unfortunately, Mac OS X has some peculiarities and idiosyncrasies that don't make things very easy for development of cross-platform applications. Porting some aspects of PixInsight's workspace to Mac OS X is a continuous fight. I am always working to integrate PI with Mac OS X more smoothly, but there are some parts of the GUI where I still have to work a lot. This is one of them.
Unfortunately, if I implement PI's process tool windows as
floating windows on Mac OS X (a special OS X window class that disappears automatically when the application loses the focus), then I lose some functionality that is needed. So I have to implement tools as dialogs, which don't disappear automatically. In the next version, I'll implement a routine to hide all tools when the application is inactive. Maybe I'll port this routine to the rest of platforms too, so all of them will benefit from the 'Mac way'
![smile :)](http://pixinsight.com/forum/Smileys/default/smile.gif)
Fortunately, you can use Cmd+H as a workaround. Sorry for the inconvenience once more.