Cannot connect via VPN to RB450: I get error 619

Hi,
I am new to this forum and to the Mikrotik router. I haven’t had a lot of exprience but one thing I know they are rock solid awsome routers..
I have configured the RB450 with a DSL and it is working just great.
I am trying to connect via VPN with Windows 7 VPN connection but it gives me an error: 619.. it connect and it disconnects…this what it says

*TCP connection established from xxx.xxx.xxx.xxx
: waiting for call
: terminating
:disconnecting
*

HELP PLEASE HELP.. why it can’t establish a connection..

try to play with windows firewall, enable/disable it and recheck