That I believe. I currently have a test going where I received the results with some differences to what I had. So, I had to go back double check everything a second time.

When I test or play, I tend to leave the move incomplete (flashing) while I record it in Arena or on the sheets. Only after recording do I enter its move to completion and/or take it back for correction. So, I don't have to worry too much about using up computer time.

But not everything is that simple. I have plenty of duplicate computers of many models, some of which are from same productions runs. But there are a few out there even if you do a simple using left hand and right hand hitting enter at the same time that their response when they move does not come at the same time.

So, I do believe there are other things also involved that can create discrepancies.

Ron Nelson for example (or someone else if not Ron Nelson) said, often, they used whatever was available on the shelf or from the manufacturer to complete a production order. That tells me a lot. As whoever told me this, would not be unique in this practice.

Best regards
Nick