Erick Branderhorst writes ("Bug#2451: Dpkg doesn't allow packages to change section"):
> Dpkg doesn't pay attention to changed section in control file of upgraded
> package.
This is deliberate. Use the `Update list of available packages'
option in dselect, or dpkg --merge-avail or --update-avail, to change
this.
The information in the package control file is regarded only as a
hint.
Ian.
(I'm closing this bug.)