Squeezebox cannot play my digital music library

For years, my 4 Logitech Radios and my Squeezebox Boom all behaved perfectly well. About a month ago, with no changes ot either the radios, the squeezebox of the PC with LMS on it 'refused' to find my music library on the PC. INternet radio played fine though. I tried reinstalling LMS resetting all the devices and starting again - no luck.

In sheer desperation, I installed UE upgraded on the radios and reinstalled LMS on a DIFERENT PC and they are working perfectly.

My problem is with the remaining Squeezebox. I know it doesn't work with UE Radio server thingy, so I set up a second PC running LMS and for a while it all worked. When I switched on the PC this morning and switched on the Boom, it said it 'couldn't connect, let's try again'. I did...but it mde no difference. Once again, Internet Radio is OK, but it can't seem to see my digital music library. I've disabled my AV and Firewall and that hasn't made a difference. I'm not an expert but I could see that the Squeezebox and LMS just 'weren't talking'. I've reset the Squeezebox (again!), and set everything up from scratch, but they still won't talk. I've even tried enetering the server address of 192.168.1.64 on the Squeezebox manaualy.. and that didn't make a difference.

Can anyone point me in the right direction here before I run out of patience... and hair :)

Thanks

Steve