Alex
It sounds like possably a corrupt java download, &/or L/W Prefs folder prob
First! close L/W completly, then Go, START/My Computer/local disc C:/ Documents & settings/Your User Name/Application Data/ Now Delete the LimeWire Folder.
Now! Go to, START/Set Program Access/Change or Remove Programs, now completely remove all versions of java.
Now! Use this Link to get (jre1.5.0 09) Use the off line installer NOT the (recormended) one,
http://www.java.com/en/download/manual.jsp[/URL]
Ps. Give your ISP a ring, ask if there shaping your connection to rule this in or out.
Check Your H.D dosent need defragmenting.
Do this and get back to us.
Peace.