It's either your set up or your isp by the sounds of it.

Do this test: Bug Report instructions & sample image Is it True/False?

Try deleting your LW Preferences folder whilst LW is closed & make sure your Java is up to date; instructions here: Fixes for Limewire

Can you give us a total desciption of your set up:
1. OS version? (eg: Windows 98)
2. What firewalls you have?
3. ram?
4. Hard Disk space available?
5. Connection type? (eg: dialup, broadband, cable, etc.)
6. Modem & router brand name & model numbers?
7. Where are you trying to connect from (home, school, work, etc.)?
8. What version of Limewire (LW) & Java do you have? (Go to LW's menu Help>About LW...) Will show both LW & Java version.
9. Who is your isp provider?
10. Is this a your 1st try at LW or is this a new problem with an experienced user.

Do a speed test at either of these sites & tell us what the results are: http://www.adslguide.org.uk/tools/speedtest.asp
http://www.broadbandreports.com/stest