I tried all of the above without success. I uninstalled limewire and installed frostwire which gave the same problem. Chat room works OK. I tried it just to be sure. Also managed part of a video from the frostwire network. It seems as though I just cannot conect to the P2P network. I also uninstalled Internet explorer 7.0 as this has caused me problems in the past.

System details
OS Windows XP
FW PCTools
HD Space 105 Gb free
Broadband connection
Version was Limewire Pro 4.12.11
Java 1.6.0_02
ISP Tiscali
Test worked
Connection not shared
Firewall icon is visible at bottom of page
AVG antivirus
live in UK.
Grateful for any advice