I have built an HTPC with a GA-H55-UD3H motherboard and core i3-540 cpu, Win7 64-bit, onchip video. Very unusual problem, after resume from a sleep state of longer than 12hrs, the LAN does NOT resume. A reboot is required. If the sleep state is less than 4 hrs, the system resumes normally and all is well.
I do have an overnight backup process running from a windows home server, but have tested around this possibility, and it is not the source of the problem. I have also unchecked the LAN driver property to allow the system to disable in the power management tab.
Any thoughts?