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'.