FYI - researching the same problem on these forums and discovered a post
describing changing power management settings in network adapters in Device
Manager: Intel (R) 82566DC-2 Gigabit Network Connection on my system. There
is an option under Properties where you can un-check "Allow this device to
wake the computer." Seemed to do the trick - I can "sleep" the computer and
it stays asleep. This is a REAL obscure fix for a problem that seems to be
not uncommon with a fairly evident solution to those whose business is
hardware and software, and one I'm sure Granny or Uncle Bob would not have
been able to track down to save their lives - I'm honored to be an unpaid,
non-volunteer MS Vista beta-tester...
Doc H.