This is an old problem that was fixed in 1.4.2 - see 4839812 for a lot more
information on this.

This problem reappeared in 1.5 because we changed the way that we store the graphics device names. Our fix to 4839812 was to simply disable our use of d3d when we detected that we were running on a Trident card (hacky, but there doesn't seem to be a better fix for this hideous driver bug). This worked in 1.4.2 because the hardcoded list of bad graphics devices (which currently consists only of "Trident Video Accelerator") exactly matched the start of the graphics device name (which began with the same string).

In 1.5, we store more information with the device name, so that we can identify which monitor we are on (for multimon cases) and what bit depth we are in. This allows us to store hw-acceleration information persistently in the registry. But since we store more info in the device name string, our simple pattern match algorithm fails and we do not detect when we are running on this graphics board.