iTunes/Apple TV link functions perfectly if I quit ZA, but does not work with ZA running.

WinXP, ZA10.1.101.000, iTunes 10.6.3.25, AppleTV s/w 5.1 (all latest versions).

Apple support talks about port 3689 but I can find no port settings in ZA.

Apple TV does discover the name of my library in iTunes, but cannot load it.

This forum seemed to suggest a downgrade to ZA10.1.065 would fix it, but the link led to 10.1.079 which I installed and did not fix it.

Does anyone have a solution to this, or do I have to desert ZA after 10 years ?