Norton 360 Firewall stops my Lap Top connecting to my Dell PC

I have just installed Norton 360 on my Dell PC, and since doing this my Toshiba Lap Top does not connect to my Dell PC. 

If I disable the Norton 360 Firewall on my Dell PC, then my Toshiba lap Top will connect to my Dell PC.

I am using a Netgear DG834G Wireless ADSL Router.

I run Windows Vista Home Edition on my Toshiba Lap Top and Windows Vista Ultimate on my Dell PC.

My Dell PC is connected to my Netgear Router via an Ethernet cable, but my Lap Top connects via a Wireless connection.

The problem appears to be caused by the Norton 360 Firewall.  I have checked the Firewall settings but can not see anything wrong that could cause the Lap Top not to connect.  My Dell PC DOES connect to my Lap Top WITH the Firewall ON, so the problem is in 1 direction only.

Any ideas?  I am sure there must be a simple answer that I have overlooked.

I hope someone can help!!!!!!!!!!!!!!!!!!!!!!!!!!!