I got this board when I purchased my T-Bird in April 2001. At the time, DirectX 7 was out and the board ran fine with all my games.
Nothin' to say until DirectX 8 started showing its snout. All of a sudden, new games I bought did not always run. I got MechWarrior 4- Vengeance, it ran fine, claiming to be a DirectX 8 game (it is not - it is registered as a DX7 game, but it installs DX8). I got Half-Life, Blue Shift and it ran well, until some point in the game where I was supposed to drop down to a level below. The drop always ended in my visuals going haywire and I had to stop the game. Never reinstalled it since.
Then it started getting really ugly. In July (I think) I bought Operation Flashpoint - no game at all, froze on the splash screen. Commandos 2 (August) ? Same problem. The add-on for Shogun, Total War (the Mongol Invasion - October) ? Same problem. That was the last straw - I had to find out what was going on.
I followed helpdesk procedures for OpFlashpoint, got a DX register report, sent it off to Codemasters. No response.
I browsed forums for issues with VIA chipset KT133A and found a reference to a similar problem. I sent a polite mail to VIA asking for help. Was it because I sent it to the French office in Paris ? No answer either.
Finally I sat down and said to myself : "I have to find out what it is". And I did. After several hours of blind tests, I finally found out that it is VIA's 4in1 driver set that drops the ball on DX8 games. Actually, it is only the UDMA driver that does so. Thank God the AGP driver part still works.
Anyway, I said to myself "VIA has to know, they've updated their 4in1 driver set". So, download the latest version for KT133A and install and - no deal. Still DX8-lock. Given that they had at least five months to get their stuff straight, it is clear that they will never do it.
As for a response to my mails, I've totally abandoned expecting one. Doesn't matter, I've solved the issue by changing motherboard supplier. I do think the KT266A is DX8-compatible, but I'll wait until I'm sure of it before buying a motherboard with that chipset. And, if it does give me trouble - I'll return right away. I think manufacturers pay a lot more attention to returns than they do to simple mails from a nobody who just happens to be a customer.