VPN(PPTP) setup problem

Hello I have problem to setup VPN of RB435G

Computer(A)—RB435G(AP_VPN CLIENT)---------------(Wireless)---------------RB435G(Station_VPN SERVER)—Computer(B)
Computer(C) can access to RB435G(AP) and can open Computer(A)’s share folder and receive file.
In my knowledge, Computer(C) can ping to computer(A), but cannot receive file from Computer(A).
Let me know what did I wrong?

vpn setup profile is attached.
pptpsvr-20130730-0023.zip (5.79 KB)
pptpclient-20130729-0001.zip (5.52 KB)

please post export o print output for fast reply.