I'm using Google Public DNS too. I don't really know if there is a relation with DynDNS but I'm still experiencing issues in GitHub and Twitter, like partial loading of images.
Maybe this is their strategy: we break it, you buy it ;)
https://help.dyn.com/internet-guide-setup/
If you can't load that page, the public DNS servers are: 216.146.35.35, 216.146.36.36