Have a look at the OLED display on the DNS-343 and note the IP Address. Trying pinging that IP address from your workstation. If you get a response, try connecting to the DNS-343 administration website (http://###.###.###.###).
If you are successful, note the network configuration information (Workgroup name, IP, etc.). Compare that information to what is configured on your workstation. Other than the IP Address, the remaining network configuration (Subnet, Gateway, Workgroup, etc.) should be the same.
If you are using the EasyShare utility (I don't), make sure that any required TCP/UDP ports are not block by the firewall on the workstation. Also verify that the version of EasyShare you are using is fully compatible with Vista64.
HTH,