Firewall Conflict

I've been wondering. I have ZoneLabs personal firewall installed on Windows. I also leave the default XP Pro firewall enabled on my internet connection. Is it possible that the two could cause a conflict in any way?

Also, if anyone knows of a really good open source firewall for Windows, I'd be interested.

http://sudhirmangla.i6networks.com/p...l/Firewall.htm

Theres one. : )

You can test your port status at:

http://www.grc.com (take the "Sheildsup" test)