I've just upgraded my VirtualBox 2.1.4 on Kubuntu 7.10 as a host to 2.2.0. I have Windows XP running as a guest.
After upgrading (and also upgrading the guest additions), I've noticed that 2D acceleration was not active anymore. Dragging a window spikes the cpu enormously, swithing between windows is slow, even scrolling a webpage is terribly slow.
Anybody who has worked with an operating system when the graphics drivers were not installed, will recognize this behaviour. This happens when there is no 2D acceleration from the graphics card activated, which means that the CPU needs to calculate all the (re)positioning of moving pieces of the 2D elements of the various windows etc.
Is there a specific reason why it does not work anymore on my machine? This slowness is unacceptable.
It might have something to do with the 3D acceleration support: At first I saw it was enabled when I upgraded to 2.2.0, but even when I deselected it the 2D acceleration was still not functional.