One website started overriding domain mapped sites?

I have a Wordpress network. All of a sudden in Google Chrome all 154 of my domain mapped websites were pointing to the same subdomain "Not Domain mapped!". I'm currently running on Nginx after switching from apache. After I restarted my server the bug went away. Cacheing? Not sure! I just updated to the latest domain mapping version. I was using 4.2.0 or something like that.