Please try "Berichte -> Aktiva & Passiva -> ReinvermÃgen Balkendiagramm". What does the title read? My system only shows "Reinvermgen Balkendiagramm", the umlauts are still missing... What is showing on your systems?
It's showing as expected with de_DE and de_CH.
If I'm understanding you correctly, the issues don't seem to be bugs in gnucash. If so, you might ask Thomas to close this bug report.
Kind regards
T. -- Thomas Viehmann, http://thomas.viehmann.net/
