NIS 2009 Intrusion Prevention blocks router?!

I just purchased NIS 2009 (updated to 16.2.0.7).

 

Immediately after installing it, my internet would get blocked…including network access to my NAT.  After playing around with it and a few reboots it seems the problem is that the “Intrusion Prevention” blocks my router(!).  For a minute or two after loading windows, my internet is working fine.  Soon after it gets blocked.... completely.   Not even DHCP goes through.  If I disable Intrusion Prevention and reboot, it works fine again.

 

Any insights?  It's crazy.

 

If it helps:

Vista Ultimate 32bit.

Connected via Ethernet to Router with NAT + DHCP.

 

Internet works fine with other machines connected to the same router.