Configuring ZoneAlarm With A Router

I have been using ZA for several years with my cable modem and it worked great. I'm getting a second computer soon and wanted to network so I bought a Trendnet 4 port router and plugged my single machine into it to test. It works fine for awhile when I boot the PC. The problem is that the router occasionally pings the PC to see if it is there, and ZA blocks it. Then, if the PC does not use the internet for some time, the router drops it and I am forced to reboot.

The router's IP is 192.168.1.1. I have defined the subnet 192.168.1.0 as a trusted zone in ZA but am still having the same trouble. Is there a way I can reconfigure ZA so that I will not experience these occasional drops?

Thanks for the reply. I added the specific IP address of the router and that seems to have done the trick. I'm now essentially using the router's hardware as my firewall and ZA is only enabled to catch programs that try to send data to the internet without my knowledge.