PPTP Site to Site VPN question

Hello.

I have a site to site VPN using PPTP all works fine and is stable between a Draytek 2830 and an RB2011 using version 6.37.

I have experienced an issue where by if the VPN drops for any reason the connections are still held open between the client and the mikrotik. The only way i can get the clients to establish connection over the VPN is if i go into Firewall-Connections and kill any connection to the remote site they will keep timing out. The Mikrotik can always ping the remote site and restores every time when the VPN is dropped.

My question is, if the VPN drops is there anyway getting the states on the Mikrotik to drop when the VPN disconnects.