Since I griped about GNOME earlier, I thought I'd put in a good word for the more recent versions on potato. It now seems to be tracking sessions much better. I can delete windows and they stay deleted whenn I log on (before I had about 6 xman windows). Also, the windows stay in the correct page (not sure of the lingo--the different virtual screens) between sessions, instead of all huddling up into the initial one.
I also don't know if I should thank the Debian packagers or the GNOME team for these improvements, but, anyway, thank.