Media Receivers not showing in Configuration

[Manster62]

Hi, I have been happily using Twonky Server for a few months now, without any problems. However, I have just changed my network and now I am finding that no receivers are showing in the Configuration pages. I have a LGBD570 BluRay player and have been using it to play my i-tunes playlists from my Apple mac. When I look at the servers list on the LG it shows the Apple Mac and relevant folders (not playlists) but not the Twonky Server.
I admit that, with my new network, the signals to my i-mac are not as strong as they were (awaiting a firmware update to the router, but that's another story.....) - is this likely to be the problem?
When I use IP Scanner to check the devices that I can view on my network the LG Player is there and I know the IP address - can I set this up manually and, if so, how? Sorry, I couldn't find any instructions on how to do this.
Any help would be much appreciated.