The problem seems to be with sshd. I should say that I may have caused this problem myself by installing Bastille-linux, this after listening in to a discussion about security on the mailing list. I've asked their help, and they suggested that I uninstall Bastill-linux, which I did as best I could. But, it is entirely possible that some is still left. Or, Bastille-linux could have nothing whatsoever to do with my problem.
Any suggestions are very welcome.