You said "But after I typed in summary and published several hubs, the missing summary (A) shows up in my hubs statistics."
I don't know what's happening in there, but it should have been there when you click "done editing." Maybe you have an internet connection problem. If you lose you connection, it won't be saved. You'll just have to repeat it.
You can help the HubPages community highlight top quality content by ranking this answer up or down.