I did download the latest version (2049) and I was playing de_dust just fine (besides the fact that the ct's wouldn't even go near where the bomb was planted and that if a bot plants the bomb, he gets stuck on it).

Anyways, I then typed in "changelevel de_dust2" and I played a few rounds without the bots. But then when I tried to add them, it said it was an unknown command to addbots.