Internet Time Update

I am having an issue where my Windows Vista box cannot update with an
internet time server. I have tried to unregister/register w32tm, did a
portqry on 123 UDP and received listening/filtered, etc... I am not sure
what else to try. I get nothing in the event logs for w32tm, just errors
stating no time data was available or an error has occured in the date/time
UI. Multiple ntp servers have been tried.

Can anyone point me in the right direction of how to get this working? I
even turned debugging for w32tm on but nothing that stands out. But then
again, I don't know what I am looking for.

Thanks
Mark