I have a website which I've made an image from and loaded that image onto two VM's - each configured exactly the same.
One site is configured with my domain - mydomain.com - with the A record pointing to it.
The other is accessed by the Azure VM url - mydomain.cloudapp.net.
When I change the dns A record and point it to the faster, errorless, system, the problems follow it.
Not sure why these types of issues would be impacted by DNS.