From my experience, you do get strange events happening for up to 2-3 days after a DNS change.
There is nothing to change within the Wordpress core. There is always a possibility that a plugin may store the IP but that should not stop you accessing your site.
You could try flushing the DNS on your PC. From the command prompt (assuming windows) type ipconfig /flushdns Depending on your Windows version, this may need elevated privileges.