That is a extrange one for sure.
I heard trough some postings that there is way to make your Quintum gateway “crash” by sending a storm of packets to your port 1720.
It looks like that address on the internet may be “beaconing” your I.P. address.
Make the following test: Change your I.P. adress on the Quintum and see if it stays Up or not.
Or reject that I.p. address on the router, such a way that the packets will not reach the gateway.
If the Quintum stays up without alarms on a diferent I.P, looks like some is sending a lot of trash to your I.P.