It seems to be working suddenly. Englishal your tip worked as you suggested and since then everything seems to be hunkydory
Not sure what I did but I'm not going to tinker with it any more! Thanks for all the advice everyone.
I just have one final question. The two pcs are sharing the broadband connection through the network. I currently have Kerio personal firewall running on the 'host' pc, do I also need it on the other one or is this sufficient?
Thanks again