XP firewall:

[Start]
[Connect To]
[Show All Connections]
Look at your connection(s)
If in the Icon you see a lock in the top right corner and in the title it says "Firewalled" your XP Firewall is on.

Right click the Connection
Select [Properties]
Select [Advanced]

Internet Connection Firewall
Uncheck for off.

To set up the firewall for Guntella traffic, visit this page:

http://www.limewire.com/english/content/firewalls.shtml

DG