right-click on panel Panel->Add to panel->Swallowed app... Title of application to swallow: "xload" (for example) Command: "xload" The app is swallowed correctly, although its size is not readjusted. Now logout, making sure to saving the current setup, and log back in. There is now an extra xload, which isn't swallowed. (Not saving the current setup works around it.) If it doesn't go wrong with one, try adding another swallowed app (like xclock). Sometimes it all works with one, but with two it always seems to go wrong. This also happens in Red Hat Linux 7.
I can reproduce the problem with gnome-core-1.2.4-3, *if* I save my session. If I add the applets to the panel, then logout without saving my session, things are restored perfectly. My theory is that the session manager is restarting the swallowed apps, even though they are also being started by the swallow applet. I am not sure what the correct solution is - this is a tougher problem.
I'm tempted to say "swallowing apps not designed to be swallowed is just a really broken feature and should never have been added" Anyway, not criticial enough to fix for 7.1 or 7.2, still not critical enough. ;-)