oh the humanity
In a startling discovery, I realize that Ubuntu does not exactly mirror Debian's packages. They provide their own. So all the fancy Synaptic poking around has to be on customized Ubuntu repositories. Blah. In even worse news, the latest XFCE refuses to run on Ubuntu. Double Blah. Then I discovered Ubuntu Backports, which may help. Or maybe not. Anyway, Gnome isn't that bad.
If none of that made any sense at all, sorry *grin*.