I am running ubuntu 13.10 in Virtualbox on a Windows 8 host. When my host machine sleeps and wakes, my tabs in guest Ubuntu no longer connect even after the main connection is restored.
What makes me think it's a DNS error is that I can still do google searches, and see results for new searches---but when I click through, I get an error that it can't connect:
Server not found. Try typing www.example.com instead of ww.example.com.
I /think/ this means google is my DNS and I can connect to it, but can't connect to new links.
Networking otherwise works fine, except for this restore from sleep issue.