PIX 501 VPN can’t map drives after getting connected.

I have recently purchased a PIX 501, I was sucessful in setting it up pretty straight forward. When I setup the VPN (PPTP) I can establish the connection, get authenticated and registered on the network, the tunnel. When I try and map a drive I’m getting an error that the network path is not found. I am unable to ping the internal network 192.168.1.1 throught the VPN connection I am able to ping to the connected machine(machine tunneling in).