VPN closes internet connection for all computers behind router?

[Donmulto]

I have got four computers running through a router. When i connect to a VPN on one computer the other computers lose their internet connection. I am using a Mega 105 WR router. The VPN on the one computer works fine when it is activated. When i un check the "use default gateway on remote network" setting, all the computers work fine, but my traffic is not going through the VPN on the computer where it is installed.

Thanks