Try sharing incomplete downloads.

Go to Tools>options hmm either sharing or uploads and check the box (can't start limewire right now to check where )

Also are you sharing anything. This affects downloadspeed at times

Your ISP can be trafficshaping

And last but not least. Are you running XP with service pack 2 ?
If you are have you ran the EviD Patch to increase the number of simultanious halfopen connections

Windows XP SP2 users, Please Read (Update of TCPIP.SYS on 2006-06-15)

If that didn't help or made no sense then

Try posting more specific info on setup first. Please try to answer all the questions.

Just copy/paste this into a reply with your answers

1. What's your connection like - do you have any green bars at all?
Is there a brick wall in front of world ?

2. Do this test & see if it works. What does it say ?
http://www3.limewire.com:6346

3. What are your details

OS ? (Win XP, Mac OSX etc.)
How much free harddiskspace ?
How much RAM ?
LW & Java version ? (In Limewire press Help>about LW & you'll see)
What Firewall you're using ?
Any Antivirus/spyware programs that youre using ?
Modem/router brand & model ?
Are you using portforwarding, UPnP or nothing ? (Tools>Options>Advanced>Firewall Config)
What is your listening port ? (Same as above)
ISP (Internet Service Provider) ?
Connection type (Dial-Up, ADSL, DSL etc.) + Speed Up/Down if you know ?
Where you connect from (home, school etc.) ?
Are you sharing a connection with other computers ?
Has Limewire ever worked for you ? If so how long have you been using it ?

Have you tried using any other P2P apps & if so, do you have the same problems (BitTorrent, Shareaza etc.)?

Give a detailed description of your problem. Also include any attempts to fix this. It helps people rule things out