I think the window should be consistent with the start menu; that is use the rounded pipe to join the two different elements, and add whatever else to that basic structure.
I'll keep toying around with it -- I wanted the windowframe to be consistent with the start menu, too, but I don't want the functionality of the window to be lost in all that busy-ness. There needs to be room for the buttons, and the system icon and the titlebar text. I don't want to suck up 30% of the monitor space with the design, leaving an annoyingly small window to actual function, ya know what I mean?
But I'll keep playing around with it and see if I can get more continuity between the two elements.