Your problem is there is an domain address conflict(3rd ip octet) between the clients local network and the vpn network.
It actually sounds like a security problem. Check your access lists, and make sure the addresses given out by your VPN are allowed access to those resources.
<a href=”http://http://lmgtfy.com/?q=vpn+split+tunnel”>Split tunneling</a> is not enabled. This would permit access to local resources while attached to the VPN network. This is a typical security precaution. This prevents the VPN client from being a pass-through gateway between the client network and the connected VPN network.