It's a known bug with EB 1.0, is fixed in the internal build, is one of the things MiniMe's temporary pre EB 1.1 EDB modification aims to fix.

I do not know for sure, but it might be fixed with the EDB fix the EB team has released itself (primarily to fix a bug in the Parthian goverment system IIRC), otherwise be sure to download MiniMe's mod. (Found in the sub-mods section of the fora.)