VPN Issue

I have a small VPN set up using two routers - one at each office. Previously
Using XP Pro machines in the firewall I had to change the scope of the File
and Printer sharing to 192.168.0.0/255.255.0.0 then the computers could
"see" each other. Now I have a Vista PC on one end (192.168.0.253) and still
have XP Pro at the other (192.168.1.1) but although I can ping 192.168.1.1 I
cannot access any of the shares. Remote Desktop works fine. and I can see
192.168.0.253 form 192.168.1.1 All othe XP Pro machines at both ends can see
each other fine

The error message I get when diagnosing the problem is that a remote
firewall is blocking File and Printer sharing (SMB) and that Windows has
confirmed that firewall on this (Vista) computer is configured correctly but
only the Vista pc cannot connect to 192.168.1.1 so that cannot be right.

I have tried disabling the firewall on the Vista PC but ot makes no
difference.

Help Please!