Intermittent freezing

Intermittently, my PC freezes for a few minutes then it becomes usable again. This issue is infrequent, maybe once or twice a day, but annoying when it does so. In the System Event logs, the error message is:

----------
Log Name: System
Source: iaStor
Date: 18/11/2012 12:29:32
Event ID: 9
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: Black_Widow
Description:
The device, \Device\Ide\iaStor0, did not respond within the timeout period.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="iaStor" />
<EventID Qualifiers="49156">9</EventID>
<Level>2</Level>
<Task>0</Task>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2012-11-18T12:29:32.518898100Z" />
<EventRecordID>504316</EventRecordID>
<Channel>System</Channel>
<Computer>Black_Widow</Computer>
<Security />
</System>
<EventData>
<Data>\Device\Ide\iaStor0</Data>
<Binary>0F0028000100000000000000090004C011111111090004C0010000000000000067452301EFCDAB89010000000000CCCC2A00B0CD80032040000000003C000000030000004526C2E80300000091CF42FB</Binary>
</EventData>
</Event>
------------

When looking this up on the Net, explanations to this error description suggest a an faulty storage device or controller, but how can I tell from this error message (or any other way) which particular device is causing this, or if there is any other cause of this?

My system specs: motherboard = Asus P8Z68 Deluxe; CPU = i7-2600K; 16 GB RAM; Operating system = Windows 7 Ultimate 64-bit; system drive = 120GB Corsair Force Series 3; two additional Western Digital hard drives; graphics card = 1536MB MSI GTX 580 Twin FrozR II/OC.

Let me know if any other information is needed in order to rectify this.

Thanks.

You forgot to list your power supply...

My PSU is Corsair AX Professional Gold 1200 W. I think that's more than enough to drive my system.

I forgot to mention, when I get the temporary freeze, my HD light is continuously on during those few minutes.

One of those Western Digital hard drives may be going bad, loading the SATA interface. Disconnect the drives and see if the freezing stops

Why are you quoting your original post, without doing anything suggested?

Is there a way I can find out from the logs which hard drive is going bad, without the trial-and-error of removing any to see which resolves the issue? The issue is very intermittent and infrequent, so it could be days before I decide I've found the correct drive that way?

Sorry that one was in error, didn't mean to quote my original post. Please ignore that one.

Just unplug one hdd at a time. They are SATA so they have a power cable and a data cable. You need to disconnect both cables. Because of the nature of this problem, you have to run with one hdd for a while then reconnect it and run with the other disconnected until the error BSOD happens