Port Explorer breaks network

I've recently installed the Port Explorer demo and I can't say if I like the program or not, as it totally broke my network after installation.

I've actually tried to install the program before and had the same results, but I was hoping it was a bug that had been worked out.

After installing Port Explorer, there is absolutley no internet connectivity. Everything else seems fine, but there's no net... I uninstall Port Explorer and everything works again.

The computer I installed port explorer on is running WinXP Pro SP2, along with NOD32 and ZoneAlarm and I'm behind a router (standalone PC, not networked and MS Networking client is removed) on a cable modem connection.