I had this exact same problem. In fact it was worse than what you reported as it was also causing blue screen crashes. I have an Intel P45 based board with an ICH9R. I also had attached to this board a SATA LG Blueray drive. From what I gathered there is a problem with either the Intel Chipset drivers/Martix software or the chipsets themselves that causes LPM power management requests to be sent to drives and if the drive does fails to respond within a certain time frame it reports this as an error in the event log. However in my case it also caused the system to crash. I noticed this behavior in TWO systems based on the G45-P45/ICH9R chipsets. I tested memory, hard drives, even swapped out memory and hard drives to isolate this problem. It was completely solved by removing the SATA optical drives from the ICH9R controller.
I used the boards built in IDE controller and attached some IDE DVD drives instead on both systems and have not seen this event log error since. Nor have I seen blue screens referencing iastor.sys. I hope this helps.
Thanks for the info. My wife's notebook (also a Lenovo) has an ICH9M as well and does the same exact thing. She did originally have a BSOD with hers, but that was with an older driver. The latest one hasn't BSOD'd on my or her machine, it just posts the events every so often.
I think Intel has a bug in this driver that they need to work out.
Is there a way to disable LPM? What would the effect of this be?
this is a very popular problem. http://www.google.co.uk/search?hl=en&q=iastor+event+9&btnG=Search&meta=
some users have reported that downgrading/upgrading theSATA controller drivers to verison 8.2.x has helped. http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&ProductID=2101&DwnldID=16013&strOSs=44&OSFullName=Windows*%20XP%20Professional&lang=eng
but this is rather odd, especially since there are reports on the google results above that the driver 8.8 is broken when you would think that it implements all the changes in the previous versions....
After installing an Asus mthrbrd P45 Raid 1(Win 7), crash after crash, after crash, tried everything I could, what do you think fixed the problem so far, driver 8.2. Intel fix your problem it's not Asus or seagate or philips, it's your PROBLEM!!! The system that would go stupid, with driver 8.8, now has run for a week with no degrade/rebuilt raid error insight. I too tried 8.8, 8.7, 8.6, ->8.2