Network issue

I am trying to figure out a problem with a clients network.

The problem is that I have 4 workstations, all running XP.

All of the XP machines are working fine.

There is 1 Tosiba laptop running Vista. The laptop sees the network. The laptop can accsess the server. The laptop can create files on the server and delete them.

When I mapped the network I see the laptop from the server. And I see all the shares on the laptop. When I try to open the shares from the server I get an access denied mesage.

I checked all the network settings on the laptop over and over.

Network discovery...on.

File sharing...on.

Public folder sharing...on.

Printer sharing...on.

Password protected sharing...off.

Media sharing...off.

Also when I tried to run the windows backup, from the laptop to the server it ask for a user name and password to gain access to the shares on the server.

There are no passwords on any system in the network. Therefore I cant setup windows backup.

So! The server cant open the laptop even though it mapped it. The laptop can open any shares on the server.

And yes I checked the permissions everywhere. I allowed full access to everyone.

What am I missing? This should be cut nd dry.

Any help would be awesome.