DeadJohn, I have a similar issue. In my case things seem fine in flight but at the VAB my numbers are as out of wack as yours. ISP, Thrust, TWR, delta V, and Burn are all much too high in KER. If they were correct, I could send my little orbiter satellite to escape the sun. For the record, I am a noob. I'm running Vanilla 1.8.1 with KER and Automated Science Sampler, so it's quite possible I screwed something up-- except you seem to have the same issue.