Dear Marcello,
You are running with old SP level (SP04). The problem with NW Java is the patches for specific SP aren't always updated and certain components get updated via SP only.
This is the case for your issue. You have updated the ENGINEAPI to SP04 PL21 which is available at 16.05.2013 but the DI_CLIENT for SP04 only has updated at 08.09.2011(SP03 PL01, there is no PL03). I think the only option you got to solve this issue by implementing SP.
Best Regards,
Achmad