It more than likely is Vigin Media that is blocking your connection as they are known to do this...
Traffic management
There are a few things you can try though...
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
Also try deleting your preference folder/s...
Fixes for Limewire when LW isn't operating as it should
Could you also supply the model number for your modem so i can check to see if it has a Nat Firewall...