Hi,
Google "hyperthreading", there are pages and pages of reported problems. If there isn't a BIOS upgrade or Main Board driver update, just disable it, end of problem.

BTW the problem only occurs during intensive operations, in the photoshop scenario it was when doing intensive rendering of an object with the mouse.

>Do you have any details on this?
>
>Thanks!!
>
>>Hi,
>>It is an old bug with HT, check for a BIOS upgrade to fix it. Photoshop also has the same problem with it.
>>
>>UPDATE: If you run task manager you will see a second thread spawned for the app then the second thread dies, causing the hang.
>>
>>>We have an application that is hanging on a system with a hyperthreaded processor. This application runs fine if you turn off the hyperthreading.
>>>
>>>When I say "hanging", I mean just a complete lockup. It freezes the whole system... does not crash - you have to turn off the machine.
>>>
>>>Has anyone experienced this?