> Something's not right here (or with sizeHints) when first starting:
> 
> http://imgur.com/XipVdgz
> 
> The bright bar at the top is actually the dash on startup...
> 
> Here's all logs when I switch to windowed mode (staged mode looked fine):
> 
> $ cat unity8.log
> qtmir.surfaces: MirSurface[0x25da7a0,"unity8-dash"]::setFocus(false)
> file:///usr/share/unity8//Stages/DesktopStage.qml:252:9: QML CrossFadeImage:
> Binding loop detected for property "sourceSize.height"
> qtmir.surfaces: MirSurfaceItem::MirSurfaceItem
> qtmir.surfaces: MirSurfaceItem::setSurface
> surface=qtmir::MirSurface(0x25da7a0)
> qtmir.surfaces: MirSurface[0x25da7a0,"unity8-dash"]::registerView(36788008)
> after=2
> qtmir.surfaces: MirSurface[0x25da7a0,"unity8-dash"]::setFocus(false)
> qtmir.surfaces: Setting keymap with empty layout is not supported
> qtmir.surfaces: MirSurfaceItem::setOrientationAngle(0)
> qtmir.applications: Application::setInitialSurfaceSize - appId="unity8-dash"
> size=QSize(-1, -1)
> qtmir.surfaces: MirSurfaceItem::MirSurfaceItem
> qtmir.surfaces: MirSurfaceItem::setSurface
> surface=qtmir::MirSurface(0x25da7a0)
> qtmir.surfaces: MirSurface[0x25da7a0,"unity8-dash"]::registerView(37781296)
> after=3
> qtmir.surfaces: MirSurface[0x25da7a0,"unity8-dash"]::setFocus(false)
> qtmir.surfaces: Setting keymap with empty layout is not supported
> qtmir.surfaces: MirSurfaceItem::setOrientationAngle(0)
> qtmir.surfaces: MirSurface[0x25da7a0,"unity8-dash"]::setFocus(true)
> qtmir.applications: Application::setInitialSurfaceSize - appId="unity8-dash"
> size=QSize(180, 126)
> qtmir.applications: Application::setInitialSurfaceSize - appId="unity8-dash"
> size=QSize(0, 126)
> qtmir.applications: Application::setInitialSurfaceSize - appId="unity8-dash"
> size=QSize(0, -108)
> 
> ^^^^ this looks wrong
> 
> qtmir.surfaces: MirSurfaceItem::~MirSurfaceItem - this= qtmir::MirSurfaceItem
> (this = 0x24c8c18 , name= "surfaceItem" , parent = 0x0 , geometry = QRectF(0,0
> 1920x1146) , z = 0 )
> qtmir.surfaces: MirSurfaceItem::setSurface surface=QObject(0x0)
> qtmir.surfaces: MirSurface[0x25da7a0,"unity8-dash"]::unregisterView(38571032)
> after=2 live=true
> qtmir.surfaces: MirSurface[0x27077e0,"-"]::resize old (1920,1146), new
> (1776,1146)
> qtmir.clipboard: D-Bus GetContents - returning 0 bytes
> loadExtendedAttributes: menu item does not contain 'x-canonical-scroll-action'
> loadExtendedAttributes: menu item does not contain 'x-canonical-secondary-
> action'
> loadExtendedAttributes: menu item does not contain 'x-canonical-scroll-action'
> loadExtendedAttributes: menu item does not contain 'x-canonical-secondary-
> action'
> loadExtendedAttributes: menu item does not contain 'x-canonical-scroll-action'
> loadExtendedAttributes: menu item does not contain 'x-canonical-secondary-
> action'
> loadExtendedAttributes: menu item does not contain 'x-canonical-scroll-action'
> loadExtendedAttributes: menu item does not contain 'x-canonical-secondary-
> action'

I think you may have hit the same problem I was seeing with windows getting small geo when switching to desktop mode in the form factor work. There's a bug in the Desktop stage which screws up the requested height/width.

My fix is here (not 100% sure it's the same issue though): http://pastebin.ubuntu.com/15007899/