has anyone encountered a bug where your tech gets scrambled? I was trying a high population game on earth, and in 1887, I got a science message to pick a tech. One of the choices was alphabet. An odd option as I had already discovered railroads and was happily laying track through India. I looked at my science advisor on the next turn, and I have lost many techs, including alphabet, writing, the republic and railroad, but have inexplicably gained some techs such as computers, nuclear fission, and metallurgy. The tech changes described are a sample, not all inclusive. Any ideas what happened, and short of a save reload, how to fix it?