SD's second article has a link to firewalls .. guess what? thats what it was. I have disabled the firewalls on both PCs and the shares are all there
Im running connected to the internet and feel a little vulnerable like this although the hardware firewall of the router should be doing its job. Further on in the article it mentions selecting the ports you want to open to allow the PCs to network without having to actually disable the firewall completely. Where do I find which ports I need to open?