Comment 39 for bug 674138

Unity with sloppy focus is severely broken - it breaks Eclipse popup-windows (any RCP based product, not just the java IDE) - javadoc, Ctrl+O, Ctrl+F8, Ctrl+3 - all broken if the mouse pointer is in the area the popup window will appear. What happens is that the window appears but is instantly closed, giving you no chance to provide input to that window (mouse or keyboard), nor read anything.
Terribly annoying since the only viable solution is to enable click-to-focus.