Firewall blocking traffic even when not running!?

I installed Comodo Internet Security v3.13.121240.574, firewall ONLY.

From then on, my FTP and email stopped working. Even when I shutdown the firewall (shield is gone from system tray).

I tried ping in a command line window. The first ping attempt ALWAYS fails. The last 3 always succeed. No matter what site I try. Why is this happening even when CIS is not running? (BTW, i rebooted the machine, router, and modem several times)

I uninstalled CIS, rebooted, and everything went back to normal. All pings go through, etc. What’s going on?