Well, that's not terribly reliable either. For example, can you download all those 6 versions for the Humax from their web site?
I know you can't download many of the versions from the Topfield site - or rather, they're there, but there are no public links to any except the latest ones that work on all TF5800s, regardless of tuner module. I presume Topfield did that so that they don't have the problem of people downloading a firmware and finding that it doesn't run on their unit.
But that doesn't mean that there have only been two firmware releases, does it?
That's the issue; I've seen people on this forum and elsewhere, for example, claim that the number of firmware releases over the lifespan of the product somehow proves either a) their favourite product has the most responsive manufacturer ever, in the whole world or b) their not-favourite product must have the buggiest firmware, or be orphaned, or something else.
Personally, counting firmwares seems to me to be one of the least reputable branches of statistics, but if the tables going to have numbers in there, it would help if they were clear about exactly what is being counted.
Nigel.