As you can see in the following output, xserver-xorg-core/experimental depends (thru xserver-xorg/unstable) on input/video drivers which are all depend on virtual packages like xorg-input-abi-7.0 and xorg-video-abi-6.0 that are only provided by xserver-xorg-core in unstable... -- Linux box 2.6.35-l1-l1 #1 Mon Aug 23 22:37:37 IDT 2010 i686 GNU/Linux