Others have reported it as well. If you've already logged it with gc2bugs, it'll be on the list of things to look into for the coming update.

Very interesting observation Evil Roy. I think I have some notion of what is going on. After looking at the Tech Tree XML files in just a regular XML editor (rather than in the GalCiv Tech Tree Editor), I found that the race specific tech tree files do not have all of the fields for the "generic" (that is non-race specific) techs. In particular, they do not have fields for the prerequisite techs. If you look in the folder above the TechTrees folder (i.e. Twilight\Data\English rather than Twilight\Data\English\TechTrees), you will find a TechTree.xml file. This file appears to contain all of the "generic" techs, but with complete sets of fields (such as for prerequisites). One thing that I found when using the Tech Tree Editor is that it can be amazingly "prescient." At one point I was playing around making a custom tech tree in which I was "cherry picking" tech from various races. I discovered that as I was typing in internal ID's for techs, the editor would automatically fill in the remaining fields for the tech, even though that tech did not exist in the XML file I had open. Unless Stardock has gotten good enough at AI programming to make it psychic, the conclusion is that the editor (and presumably GalCiv) must be referencing another XML file. My assumption is that it is referencing the "generic" tech tree XML file outside of the TechTrees folder. This way, the race specific tech tree files need only have data fields that contain differences from the default (I presume for memory savings). Perhaps, what may be going on is there is a glitch in the editor referencing functions such that it is grabbing the wrong prerequisite techs from the "generic" XML file, hence the Adamantium II prereq for Adamantium I business. Anyway, just my thoughts, which might be completely garbage.

If I am on track, I hope this helps the devs.