Hello,
I have a similar problem. I, for some reason, uninstalled b4i-bridge from my iPhone. When I tried to install it from my mac, my phone refused to connect to the mac (i.e. address given by the server is not reachable from my phone). They are both in the same network and my pc can connect to both :51041 and :51041/test. The real frustrating part is that I was able to easily connect to my mac last week. I don't know what causes this.