I have a dual monitor setup at work with my primary screen below my secondary screen.  My primary screen has a task bar on the top and bottom of the screen.   If I only have my primary screen connected everything works as expected and my maximized windows treat the upper task bar as the top of the screen.  If I enable the secondary monitor maximized windows seem to treat the screen edge as the top instead of the task bar and the window decorations get lost (they are under the task bar)

Reproducible: Always

Steps to Reproduce:
1.  Create a task bar on the top of the primary screen
2.  Attach a secondary display above the primary
3.  Maximize a window on the primary display
Actual Results:  
Window decorations are behind the task bar.

Expected Results:  
Window should treat task bar as screen edge.