To everyone having trouble with the game:
After quite a long time experimenting I finally succeeded to overcome *all* problems with the game. I mean it's no problem anymore to play it through, no hangup, no crash, no lock anymore.
So what I did was really changing hardware. I'm now using an Intel BX chipset featured motherboard and an Intel Celeron 500 CPU. I already had 128 MB RAM and a Matrox G400 AGP graphics adapter.
Here is the info I found at several places. If you have trouble playing the game, I really suggest to compare your setup with this list:
* If you're using a mainboard which has an ALI Aladdin V chipset in combination with an AMD K6 CPU, this combination may cause a lot of problems. At least with my Matrox G400 adapter the game always crashed about after 15 minutes of playing, I heard the same concerning a Riva TNT adapter.
Please note that there is no solution apart from changing your mainboard. The Aladdin V is too old and does not correctly deal with modern 3d AGP graphics adapters. The AMD K6 seems to make it even worse.
* I heard about problems on machines that have less than 64MB RAM. I could not prove that yet but if your system has only 32MB RAM and you encounter hangups or crashes maybe you should add another 32MB to get rid of these problems.
* The same seems to apply to graphics adapters with "only" 16MB or less of video RAM. Again, I heard about problems related to this from other people (which disappeared after a 32MB adapter was installed) but could not prove this yet. But if the game suffers from what software developers call "memory leaks" (a program uses-up all available memory by time, finally crashing when memory is exhausted) more RAM would give your machine more stability.
* After all, the 1.2 "update" (I'd rather call it a vital bugfix) is a *must*. You can obtain it from ftp://ftp.lucasarts.com/patches/pc/J3DUpdate1.2.exe (after downloading, just doubleclick it and it will automatically install).
Initially, I was not very excited about changing hardware just because of Infernal Machine, but this really improved my system's overall stability so it was worth the trouble.
Hope this helps - bye bye, Roland