I figured out why, its because you're changing their names. Or epatath (however its spelt) or more likely both. Fortunately I was mistaken when I thought I had to define the name to switch era so I get the description back
If you drag dom3.exe onto notepad or emacs or whatever you can copy and paste the descriptions. Easiest way to find them would be to search for a sentance
Now back to figureing out how to set unwanted magic paths back to zero after a copystat...