Windows 7 Windows 7 64 bit and NAS

[torq]

I have a NAS (Western Digital MyBook World Edition) and recently I've upgraded my OS to Windows 7 64 bit (from 32-bit Vista) and I'm experiencing strange problems with NAS presently.
When I start it up while Windows is working the system discovers it and allows access, but when I shut the computer down or merely switch it to sleep mode, after resuming I cannot see my network disk and I cannot access it (though it pings perfectly). It can only be cured by restarting the NAS.
On 32-bit systems everything works as clock. Is there something with 64bit OSs which may cause that?
I contacted WD support but they're pointing fingers at Microsoft saying 'it's not our problem'.

 

[Trouble]

First make sure that the network attached storage device has a static ip address.
Next time the problem occurs, on the problem windows 7 machine
clear the netbios cache (open command prompt and type nbtstat -R)
then ping the nas by IP but include the -a switch (command prompt type ping -a 192.168.nnn.nnn) use the actual ip of nas
this should return the netbios name of the nas in the first line
now ping the nas using the name
now examine the netbios cache and see if it is accurate (command prompt type nbtstat -c) is the ip address and name present.
make sure that netbios over tcp/ip is enabled in the properties of IPv4 in the properties of your network adapter
make sure that the tcp/ip netbios helper service is started and set to automatic
make sure that any QoS features available on the common router and or on the nas itself are enabled.