home sharing error 5599

Hi,

can anyone help on this, i have just had to reset my brothers Apple tv 2nd Gen (model no A1427), because of a problem with movie genres disappearing...and i now get the error message of 5599 when trying to setup home sharing on win xp machine...I have the latest version of iTunes, the apple tv os is v7.0.2...I have tried resetting his iTunes password, de-authorising his iTunes collection, then reauthorising it, rebooting his router and have to say am unsure what to do next...

any ideas...