Hi Cipherplain, No, in the end it turns out the mac had a different "identity". So I was able to share the mac directory with the server (the webGUI) via one of the normal sharing keys, but I guess because the mac had a different identity it wouldn't sync from the server to the PC. I had to remove BTSync and reinstall it, and pretty much remove all traces from it so it started with a new profile which I then linked with the existing identity from the server. After that it synced with all devices. Pretty confusing and a shame there's no way to merge or change identities in the GUI. Much preferred the old way, with sharing keys for folders, but glad it's working now. Thanks for your responses :-)