@sek
it's reasonable to disable software firewalls when trying to get shareport to work, since often times, the software firewalls are creating the problem. At least it can then be isolated.
Running a software firewall on top of the router firewall is a bit redundant anyway, and only really provides extra protection within the network, as in if some computer already on the network had a virus or someone hacked into your network with a virus or worm, or a friend came over with his infected laptop and got on your network, infecting your computers. If such events seem unlikely in your case, you may not need a software firewall.
Plus, many people having problems on these forums are running multiple software firewalls, either because they don't realize windows firewall is set to run by default when they installed their resource heavy virus software (i.e. norton etc.) or they think that two is better than one. You should never run multiple software firewalls, one is plenty. And there is very good reason not to even run one software firewall, unless you want to constantly be troubleshooting it. I have disabled my windows firewall completely since I got tired of troubleshooting it and I just don't see what it is really doing for me on top of my router firewall.
Best thing is to get a resource lite virus app and skip the software firewall, unless you just really want it. Try avira, which has a very good free version. Nod32 is also very good, but no free version. I run Nod32 on my main computer, and have installed avira free version on my laptop and it has never caused conflicts with other programs and is very lite, and it's updated daily, often several times daily. (If your virus protection isn't updated daily, it isn't doing much for you.) This will save you many headaches. Maleware infections are probably 90% caused by user activity (**** sites, torrent sites, downloading hacked software, warez) and if you avoid those activities, you are going to be very unlikely to get infected. The virus software is a last resort for protection. Your behavior is either going to protect your computer or put you at risk.