I have made a mistake. I changed domain registars from Network Solutions to Gandi. The record is properly configured at Gandi and all of the "alternative" name servers (google, opendns) have updated and work properly. However, the major ISPs in my area (Belgacom or EDPNet) are still querying the Network Solutions name servers and returning a "domain not found" error. Effectively, the site is not available for most people.
Is there any way to expedite this change? If not, is there any way to tell how long these name servers will wait before they start querying Gandi?