Well, its been a bit of a while, but I think I have this one finally fixed.

The problem has been that when I moved to using SSL (ie., encrypting all traffic to and from the site) although I changed the WordPress configuration file (wp-config.php) to the new address (https://veltman.org), the underlying entry in the mySQL database still pointed to the original site (http://veltman.org).

To fix it, I had to change the following table entries:

In the table wp_options:

siteurl    https://veltman.org
home       https://veltman.org

Both needed modification as they were still pointing at the original http://veltman.org address. This was enough to confuse WordPress at the time of login