VNC on VirtualBox

When I use VirtualBox with VBoxHeadless over VNC (not RDP, since I'm using OSE (Open source Software Edition)), mouse cursor is often out-of-sync by default. (i.e. host mouse cursor is away from guest mouse cursor)

To fix this issue, I've been using '--mouse usbtablet'.

VBoxManage modifyvm vmname --mouse usbtablet