Hi there, i had a problem with my Acer 4740G. I was not using the computer for a while, and then computer screen suddenly turned dark. I thought the computer went to sleep. However it does not respond to clicks, and key presses. The only solution is to force shutdown the machine using the power button. It happened 3 times, yesterday. I thought it might be some issue with Acer hardware going overheating etc.
However, today there is a new update for Windows 7. (27 Jan 2010)
http://support.microsoft.com/kb/977074Reliability update. One of the fixes is;
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On a computer that is running Windows 7, you configure the Screen Saver Settings to display the logon screen on resume. Additionally, you configure the computer to go to sleep. However, the computer may not go to sleep after the screen saver starts. Instead, a black screen is displayed. [B]This problem causes the operating system to stop responding[/B]. You must restart the computer by holding down the power button.
Also, for those who likes to put a blank desktop (solid color) - like me, the logon will take 30 seconds due to a bug in Windows 7. There is an update for that too,
http://support.microsoft.com/kb/977346CODE
The Welcome screen may be displayed for 30 seconds during the logon process after you set a solid color as the desktop background in Windows 7 or in Windows Server 2008 R2
This is however a hotfix and not distributed using Windows Update. You need to download is manually.
Since i experienced both the above problems, i everyone update their laptop after purchasing, immediately

Cheers