But if your firewalls are configured to allow LW passage you should be able to get uplds without problems. I wouldn't advise windows users to go without a firewall. Which firewalls do you have? See the most popular ones for configuring for LW here:
http://www.limewire.com/english/content/firewalls.shtml
The issue might not be or just be your computer's firewalls but also your high speed modem or router which tend to have internal firewalls (generally NAT type firewalls.) Can you tell us the brand & model number of your modem/router? They may need port 6346 opened to allow people to upload from you. If you were using advanced net games or particularly video conferencing, you'd need to open up a handful of ports. But for LW only one. But then you might not have this type of issue depending on your connection devices.