Hunh-- that does it. "Open Action Center", in this particular case. Thanks!
What I had done in the meantime was un-hide the Taskbar via ObjectDock, and hide it via the normal Windows Taskbar properties; then it comes up when I use the Start button on the ObjectDock. I use a cursor-wrap utility (so if I move the cursor off the bottom of the screen it reappears up top) with my trackball, so hovering on the edge of the screen to bring up the taskbar doesn't work so well (the space for activation is very small unless you don't have that wrap and can just jam it into the stops). The edge-hovering delay you can set in ODock works like a champ for this, BTW-- moving the cursor past the edge to wrap it doesn't send my edge-mounted taskbars flying out unless I want them to.
How about that-- I am back to Stardock's docks after beginning in the early 90's with OS/2 Warp and the Launchpad. Pre-tabbed Launchpad, at that!