OmniWeb windows and Spaces

I'm running the latest  build:  103979

I'm trying to figure out the behavior of OmniWeb in Spaces.  If I have  
two Omni windows open in a space, and the front-most window has no tab  
drawer open, but a second window (in the same space) has its tab  
drawer open, and I drag the front-most Omni window to a different  
space, the second window is also moved to the same space.

However, if the tab drawer on the back window is closed, it doesn't  
follow to the new space.

If I have multiple windows open in a single space, the same rules seem  
to apply - any/all windows with open tabs are relocated to follow the  
dragged (top) window to the new space, but any windows with closed  
drawers remain.

Is this intentional?  If so, can someone explain the rationale?

-lw