I've been playing High Treason lately and noticed an issue - I kept getting BSOD's occasionally referencing the ATI ATI3dxxx.dll drier. Searching online results in people simply using their *ss as a brain in saying buy NVidia because ATI drivers suck, yadda yadda yadda.
Anyway, I am fairly certain I got it solved - it does not like dual core CPU's or dual CPU's at all! Set your affinity to a single core and it is perfectly stable. This requires Alt-Tab'ing out to task manager, right clicking the app, choose CPU affinity, and select only one or the other CPU.
If this is a pain for you, I can fix that for you too. You will need to download the no-CD patch (The original file is encrypted and won't allow you to modify it's config - this is the first game I needed to do this in that was encrypted and wouldn't work natively) and then use imagecfg to permanently assign a single particular CPU to the game.
Imagecfg (made by Microsoft, but not distributed by them anymore) is not so well known since Windows 2000, but works perfectly fine in XP too. You can get it here:
http://www.robpol86.com/Files/imagecfg.exe
Drop that file into your Windows/System32 folder, pull up a cmd window, and pop into the Act of War directory. Type the following command:
imagecfg -a 0x1 ActOfWar_HighTreason.exe
Copy paste that into the command window if you want.
From then on, every time you start the program, the program will execute on the first CPU exclusively. If you don't like it using CPU 1 or core 1 every time (Insert you are the anal type here:p), you can use 0x2 to use the second core or CPU in place of 0x1. There is no difference between using CPU 1 or CPU 2 except if maybe you want to give a CPu a break or something from working too hard!
By the way, you can use this program for any other app you want that is having issue running in a dual CPU system. For example, the Original Call of Duty will not run in a multi CPU system. Call of Cthulhu I think also has issues on multi CPU systems. imagecfg will force it to only use one CPU forever, making it run on your system, so this is a good app to use.
Hopefully this helps someone since the information out there on the web / google / blogs is completely lacking on this subject of why games don't run on dual core systems. Also, the way to fix it is just not out there either - try googling it and you will come up with almost nothing. If you do come up with an app, it will be some app that needs to be functioning prior to the game being launched. That is a pain to me to remember to launch something before I launch something else, so imagecfg will do the same thing while avoiding the first step, and at the same time make it function without using any brain power! i need to save that brain power for the game I am about to conquer!
-S