Confusion in Mudville.
The first 21 entries (alphabetically) disappeared from the manage screen after I edited and updated my sample entry (number 21). They were still visible in phpMyAdmin. The edited entry was marked pending in phpmyadmin, and is listed as awaiting moderation on the dashboard.
When I clicked Update the screen returns to Manage with the 21 entries missing, and the entry still being listed as awaiting moderation.
Wait… I clicked further up the alphabet and then back to A so it brought back the first 20 items and then went to the moderate link above and approved the entry.
So, first lesson is Update is not Moderate.
All is good, I think, but why did the first 20 items disappear in Manage and would they have disappeared to a user of the web site? (I was too busy gasping for air to check using another browser.)