Rather than running without a software firewall, you're better off to configure your firewall
Firewall configuration instructions (click on link)

What antivirus protection are you using?

You could try port forwarding for your router. On the page below there are a few different DI624 choices...I guess you'll have to have a look through & see which suits you best.
http://www.portforward.com/english/r...outerindex.htm

Don't forget to set up a static IP first, there's a link to instructions within the port forward instructions