Seems to me both of the people reporting problems have third-party G3 upgrade cards in very old machines. That could be the cause of it.
One was using 9.0.4. I'd be interested if they tried to start up from 9.1 CD or 9.2.1 CD (not sure if they contain Game Sprockets or not) and start up pop-pop off their hard drives.
If you have access to either systems, or can have a custom startup CD made with the newer systems and Sprockets installed - it might be worth a look.
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If you think I'm being mean, please tell me. I was actually going for NASTY!!