Actually, maybe this will narrow things down, I'll list each tab and what happens when I change an item on there, some work and some don't and it may help you narrow down what's going on:
Status tab: Fully works, I can stop and start the server, change DLNA profiles for IP addresses on my local network and alter the Bound IP address
Library tab: Any changes or alterations I've made do not work, check boxes, local library, adding and removing online sources - one strange thing is that a refresh of an Online source pretty much empties the playlist viewable from my TV
Metadata tab: Fully working - I can make changes to this and they save correctly checkboxes and drop downs
Transcoding tab: Fully working - I can make all changes to this
Presentation tab: Fully working - I can make all changes to this
Remote tab: Not working, when I attempt to save a new password for remote access, I get an error message of 'Error saving data! ()' where I would expect to see the result 'Saved!'
Console settings tab: Fully working, I can change the language and enable/disable checking for new versions and it saves the changes
About tab: This appears to be fully working, an interesting point here is that the 'Licenced To:' field data is populated with '()' in a similar way to the empty parantheses given at the end of the Remote tab problem
Well, that's all I can give you right now I'm afraid.
Thanks again for this great interface!

Andy