Forum introduced a problem with diacritical characters
 

Somewhere between version 4.0.1 and the current 4.0.4 a problem with diacritical signs / characters is introduced.

My private messages used to be called (in Dutch) Privéberichten, and now are
Priv?©berichten. This problems concerns lots of phrases in my language manager

My 4.0.4 forum is a direct upgrade copy from the 4.0.1. forum. Same server, same browser. The problem occurs in the admincp as wel as in the forum itself.