Getting XP to see Vista machines

Hi, first time here so, greetings !.
I have a desktop running XP Pro SP3, with all my media files on, on a drive set for sharing and 2 laptops running Vista Home Premium. All run MS updates automatically. They all connect via a Belkin MIMO wireless router, but I cannot see the shared drive from either laptop, or the laptops from the desktop.
I use Zone Alarm security suite as AV and Firewall on all machines, and as far as I can tell all the settings are correct. I have a third laptop, running XP Pro SP3 as well, and this sees the shared drive fine. I can transfer files to this machine fine, but cannot see the Vista machines.
I occasionally get a message about XP needing an update from the Vista machines, but whe I go to MS the updates are already installed and active.
I would really appreciate some guidance as my wife is doing my head in trying to listen to music on her laptop across the network.

Thanks.

 

Take a look at these articles. The second link is a download that should fix up the XP machines.

Network Map in Windows Vista does not display computers that are running Windows XP

Link Layer Topology Discovery (LLTD) Responder

File and printer sharing in Windows Vista

 

Thanks ibmest, but already have the LLTD installed. Have all the latest updates installed, that's what is making it so annoying. Have tried everything, but still cant get either one to see the other.

 

Try turning off Password Protected Sharing on Vista machine.

 

Again, thanks Ibmest, but password was already off. Have tried setting a static ip on one of the Vista machines, and ensured that was enabled on the firewall in the trusted zone (ZoneAlarm).
Still no machines visible either way.