I was having this exact issue. I tried reinstalling, turning off the router and rebooting (I have qwest dsl), nothing worked. Then I deleted the .limewire folder in:
C:\Documents and Settings\User
restarted the program, put my personal options back the way I like, and wham it worked. I have no knowledge why this this did it. I did notice note that when I first uninstalled limewire I did not remove my personal settings. Good luck.