Can't receive VPN packets

I'm attempting to provide external support to a customers network but am having trouble with the VPN connection. The client sent me the pcf file, and I can authenticate and establish the connection. I'm using version 4.6 of the Cisco VPN client. After I connect, when I check the statistics on the connection, I can see plenty of packets being sent, but nothing is being received, and I cannot communicate with anything on the clients subnet. I've tried this on two different computers, and used three different internet gateways. The strange thing is, I've had another technician try this from one of our other offices out of state, and they can connect and communicate without trouble using the same pcf and credentials. The only difference as I can see it is our local subnets. Mine is a 172.24.x.x, our other office is on a 10.x.x.x, and the client's local lan that the vpn goes to is a 10.x.x.x. Any ideas on what is going on????