Yosemite VPN breaks internet connection over Wi-fi

I have a basic PPTP VPN connection set up, but when I connect to it, my Mac immediately looses internet connection. Skype still routes and works, but internet connection dies.

I don't have "Send all traffic over VPN connection" enabled. Even it is enabled, the internet connection is still dead.

I have the following custom routing setup in /etc/ppp/ip-up:

#!/bin/sh
/sbin/route add -net 192.168.1.52 -interface ppp0

Any advice please?