I'm not sure about 4.0, but the configuration settings for L2TP should be similar, if not the same? What sort of settings do you have for VPN? Is there a way to follow step 6 of our guide
Fill in the fields as follows:
VPN name: BolehVPN PPTP
Set VPN Server: pptp.bolehvpn.net for a US connection
Also, Enable PPTP encryption and leave DNS search domains empty.