See birdy's points made here http://www.gnutellaforums.com/showth...hlight=charter
It looks like your ISP might be to blame.

Since you couldn't download a magnet link which comes from a web site, not another LW. So it looks like your ISP is filtering & shaping LimeWire's traffic.

You have no firewall issue so it means they're not blocking the ports. You might try going to LW's menu bar, Tools>Options>Advanced>Firewalls. Turn UPnP off temporarily. Then enter 64049 in both the connection & listening ports. Then turn UPnP back on. Restart LW & see if that makes any difference. Also try connecting at different times of the day. Such as off peak times. Perhaps try both during day & very late at night to see if there's any difference. Some isp's only filter/shape during peak hours of use.

Try using another gnutella program Phex to see if you have the same problems.