How is it that I've had version 2813.3000 of SP1 for IE6 installed for months now, and everything that's been released since has had a lower version number?

I had to search the registry and change 50 - 60 entries of 2813.3000 too 2800.1041 so I could install this. When I first tried, it said the version I had was newer and it wouldn't install. I changed those version numbers and it installed fine and it seems to render the web pages faster.