That sounds like a tunnel problem. The first thing to do would be to get a copy of our Guideline for setting up a functional VPN. You will find this in our white papers section
http://www.wingate.com/files/VPN_Setup_Guide.pdf
Then, a few things that might not be immediately obvious, but which the document should highlight for you. Ensure that the VPN nodes are set to local network - if you want to share the network behind.
Make sure that your adapters are setup correctly for Internal and External (Double click to access adapter properties in the network window).
Then, because it relies strongly on routing, you might need to make some configuration changes on your client computers as well - otherwise they will not be accessible. This can be setting the DNS and default gateways, using the RIP client or using static routes. This is detailed in the document.