The '040 sometimes requires a little more fine-tuning than an '030, but other expansions in the system can also cause issues (for example a network card, graphics card, or USB card that may need additional scripting to disable prior to starting the game. WHDLoad includes some basic scripts for these).
The WHDLoad website has a complete list of tooltypes, but off the top of my head one that has worked well for me in the past is NOAUTOVEC.
