I cannot believe this, but after months of trying to fix this (on and off, trying and then giving up), it turns out that, for me, checking ON (enabled) the "Allow the computer to turn off this device to save power” worked. Got this idea from http://support.microsoft.com/kb/2560995. My guess is that the driver expects to turn the network card back on after sleep or on a cold boot, and because the option is turned off, it toggles the "switch" from being already on to off. Maybe? Anyway it works for me now, perfectly.