The odd thing is that nobody else had the sections themselves or the layer in their workspaces. And the message that came up was unusual in that it didn't identify the other user who supposedly had something in their workspace.
It didn't happen today, so maybe there was something else in those sections that was blocking me.
I just get nervous when I see something odd like this in the first couple of days of using a new version!
THEN...yesterday, another sharing oddity:
I had opened some other AC11 files at the office and copy/pasted some elements into the main file. I backed up the shared file to my portable HD as I do nightly, and working off that drive at home, those elements came up with a message saying that they were in the workspace of User #4. We only had three users, and they are our names, not numbers.
Now here's the REALLY weird part:
I saved the file as a .pln, figuring that things would "flatten out" and that I could later share the project again. I then signed out of the shared model and closed it. I opened the .pln, which seemed fine, but STILL GAVE ME THE SHARING MESSAGE!
Thinking worried thoughts of massive impending corruption, I tentatively shared the project again, and -poof- no more problems. Three of us worked furiously on the shared file today with no problems and great performance of the file overall in terms of speed.
Maybe this won't happen again, but it's a little disconcerting. Any conjectures about these behaviors? I have to wonder if my original posting issue was related to this one.