xfwm: Opening windows, and location

[Danny]

Hi!

I've got the panel non-autohide and at the top of the screen :)
To account for that I set "desktop borders", "top" to 50 pixel.

However, often new windows get opened at y < 50. 
Which makes the title bar (and a bit of the client area) of the new
windows invisible.
To get the title bar visible you have to move it with Alt+Mouse.

Any ideas why "desktop borders" doesnt apply ? :) Or do I misunderstand
the setting? ^^

cheers,
   Danny