It could have been a possible DOS attack. I don't see any other reason for this happening.
John, As I vaguely mentioned on the older thread, I've had these, from a visitor whose identity was confirmed and there was NOT any malicious intent. Rather, this person accidentally performed some option in Front Page.
I've had so few of these instances over the years that they are not of any real concern to me. On one occassion in which the process occurred multiple times from the same IP range (unknown identity), I notified both my web host and the visitors internet provider.