Hi - I'll be most impressed by and grateful to the person who solves this conundrum. Key aspects of my setup (so far as I can tell):
Dell Studio XPS 16 laptop
Windows 7 Professional SP1 64 bit
Broadcom NetLink (TM) Gigabit Ethernet
I was having a lot of problems whereby I would close my laptop expecting it to go into sleep(standby?) mode, or alternatively I would manually (thru Windows Start button) select for the machine to go into hibernation. In both cases it wouldn't. Typically what would happen is the screen would switch off but the machine wouldn't go into the desired mode, the fan would keep going etc. eventually I would have to simply turn it off the hard way by holding the power button down for a few seconds. When it came back on I would get the usual 'Windows was not shut down properly, you want to start in safe mode?' (or whatever the actual phrase is).
When Windows loaded back in I would get a 'Windows has recovered from a serious error' message, it would check online for a solution but of course never find anything. I would examine the log which simply pointed me to a minidump file which didn't appear to tell me very much.
Anyhow, I eventually found the solution to this problem by reading around the web. The issue was that, under Device Manager, Network Adapters, my built-in ethernet adapter described as 'Broadcom NetLink (TM) Gigabit Ethernet' had a power management tab with the following settings:
'Allow the computer to turn off this device to save power '
'allow this device to wake the computer'
'only allow a magic packet to wake the computer'
All three fields were ticked. The info I found on the web suggested that I should clear the tick from the 'allow this device to wake the computer' field. This I did and it seemed to be the solution to the problem, for a while... I would send the computer into sleep or hibernate and everything would be fine. I'm not sure how long afterwards, it might not have been long, the problem reappeared. I went and checked whether the power management settings for this device were as they were now supposed to be, and to my surprise found that mysteriously the 'allow this device to wake the computer' field now had a tick in it again which I had not put there. I duly unticked it, and things were fine again, until they weren't... The way I would characterise it is that every day or two (I am a power user and I ferry my laptop between home and the office so it gets closed at least a couple of times per day), when I close the lid or select hibernate, the old problem reappears and when I reboot into Windows, hey presto, the mysterious tick in the 'allow this device to wake the computer' field has reappeared!
I believe I have the most up-to-date driver for the Broadcome ethernet adapter: 188.8.131.52
Additionally, I have been through all devices listed under Modems, Network Adapaters, Ports, Sound, video and game controllers, System devices, and Universal Serial Bus controllers to look out for other rogue power management settings, but haven't found any.
I am at a complete loss as to what to try next, so grateful for any suggestions! As you can imagine, having what is in effect a hard crash every day or two is a major impediment to actually getting any work done. Many thanks, Adrian