Funny DB2 error

Sometime with DB2 and JDBC, I've got the following error:

[IBM][CLI Driver][DB2] SQL0332N Aucune conversion n'est disponible pour la page de codes source "297" vers la page de codes cible "1208". Code anomalie "1". SQLSTATE=57017

The French is not the really important part here, it's just because it's a localized version. Basically, it says that it can't convert from the codepage 297 (EBCDIC 8bits French) to 1208 (UTF-8). At first sight one can think that there is an undecodable String fetched through a ResultSet. But if the exception happens directly in execute()? It really specifies from 297 to 1208, so invalid characters in the query are not the cause. No, the errors lies in... the error message. In some cases where queries are not valid, the localized version of DB2 generates an error message which can't be translated in UTF-8, and this conversion error is reported as the primary cause. In those moments, it's handy to have a native client.