I purchased 20 copies of the edu version to run with an aerospace class that I am teaching this year and while I am doing that, I have a few students from a Jr. High class coming in to dip their feet in via the EHC. The Jr. High class gave up because of all the glitches. With those students there was a lot of failure. When they would re-load, all manner of issues would creep up. I purchased one copy off of GOG of the full version of 1.2, installed it on one of the glitchy computers and found that it works much better then the edu version. You are right though. I have found the EHC missions really glitchy. Wish they would update. Our district paid a lot of money for the 20 copies and it would be nice if it was not quite as glitchy.
On the second day of doing this with classes and am finding a bunch of weirdnesses with regards to playing. Yesterday, I had all my students play the first earth history campaign missions. I had students with issues from the autopilot not working, to big computer slowdowns, to just freezing. The commonality I have seen is that it always happens after the student has died at least once. It also seems to happen when the students pause the simulation (mission one). Thoughts? I am pretty sure that there is nothing that can be done, but I am hoping that 1.2 s released soon and fixes these issues.