Hi Gatti...
Try these fixes and see if they help...
Try uninstalling all versions of Java from the add/remove programs and then re-install the JRE 5.11 offline version....
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11
If that does not help with your problem try deleting your preference folder/s...This will reset your configurations back to default and get rid of any corruption that may of happened...
Fixes for Limewire when LW isn't operating as it should
Still no luck try removing and replacing the gnutella folder...
Birdy has the tips on how to do this in this Sticky..
http://www.gnutellaforums.com/connec...t-fix-try.html
If none of the above are successful we will look into your modem/router and ISP...