Your router is cutting out on you because it is mistaking limewire for IP attacks. Next time you launch limewire, check out your router's log file and it probably will confirm this. windows firewall is not the only firewall, many routers come equipped with one that you can also disable or allow port forwarding.

I know for sure this is the case with the Belkin wireless G router and i'm curious if Netgear is the same.