BitTorrent: No incoming connectios?

I'm using BitTorrent to download a huge file. The icon is always yellow (red sometimes) and it says there's a problem with my network configuration. The download speed hovers around 0.7 kbps. I changed my current port to 6881 and enabled encryption but nothing changed. My connection is dialup at 44kbps. What can I do to make that yellow icon turn green?