I have no idea, but a couple of guesses...
Afaik the unit name is stored by fpc (on the TObject.unitname). So the first question here is: What version of fpc? And in case it not 3.0.4, does it work with 3.0.4?
This could be an encoding issue. I.e. maybe fpc stores the strings in some ansi encoding, but Lazarus expects them in utf8.