XP cannot find Vista

>I currently have a Vista and and several XP machines on the same
> network.
>
> My vista machine CAN ping and access all shared folders on any XP
> machine.
>
> My XP machines CAN ping my Vista machine, but none of them can see the
> Vista machine in "My network Places"
>
> I tried using 'net view \\COMPUTERNAME' in the command prompt to see
> the Vista machine, but I get 'Error 53, cannot find network path'.
>
> On Vista machine:
> - Vista has Windows Firewall disabled via service.msc, and Norton
> Internet Security firewall disabled as well.
> - Network is set to Private
> - Network Discovery, File Sharing, Public Folder Sharing are ON
> - Printer Sharing, Password Protected Sharing, and Media Sharing are
> Off.
> - Under 'show me all the shared network folder on this computer',
> there are several folders, with user permission set to 'everyone' and
> there is content inside the folders.
>
> These setting should at least let me see the vista machine with the XP
> machines. I haven't the slightest clue what is going on to prevent it.
>
> Thanks in advance for your help,
>
> Pierre