Compare the presently-installed extensions with those that would be installed from the OS 9 CD—using TomeViewer to see the latter if you have to do so—in case what you believe to be stock nonetheless contains residues such as extensions for cards that were removed before you received the Beige G3. Conflict between Apple video extensions and third-party video extensions can produce the effects that you describe.

But then, why not just do a clean install of OS 9 and skirt around the problem?

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