I have just fixed an issue bothering me for some time.
When connected to vpn (using vpnc or openvpn) Fedora 19 was not able to resolve any internal name to ip address. All external addresses worked fine (and quickly resolved).
Something like this:
host server1.internal.address.com resolved the address, but ping server1.internal.address.com said it cannot resolve the address.
dig and nslookup worked fine as well.
After some investigation I found that resolver is not even trying to communicate with DNS server. Then my eyes caught process called nscd (A Name Service Caching Daemon).
My system end up with two packages installed with problem that former (nscd-2.17-13.fc19.x86_64) was not removed due to post install script failure.
So, I removed it using rpm -e --noscripts nscd-2.17-13.fc19.x86_64 and ... problem solved.
I hope this helps somebody with similar problem.