If you're using basic LW, you'll only connect to 3 ultrapeers

HughesNet will throttle bandwidth if you go over their acceptable bandwidth use threshold...that probably explains your slow speeds.
http://www.copperhead.cc/fap.htm
http://www.lastpodcast.net/2006/11/1...d-and-the-bad/

AFAIK HughesNet also offers security, including a firewall (ZoneAlarm I think). Just a guess, but if you have that firewall as part of your package, it should turn off the XP firewall automatically...which could be why you can't disable it! Sorry if this is off the mark.
If you don't have any other software firewall (1 software firewall & router firewall is ok...just not 2 software firewalls running together), just configure the XP firewall to allow LW.
Firewall setup

Just double check your port forwarding. Log into your router & go thru everything to make sure that it's as it should be.

You could change ports...no guarantee that it will change things but try if you like. In LW tools > options > advanced > firewall config. Change LW's listening port to 64049, or a port in the range of 49152 - 65535. Apply > ok. If you change listening port, you'll also have to change port numbers forwarded thru your router. Port number forwarded & listening port must be the same number.