keys that are not present in the bundle are not translated. Even though they are present in the portal translations.
UTF-8 translations are incorrectly displayed.
To test this go to Control Panel > Configuration >System Settings. Navigate through the different options to see that the keys are properly displayed. Repeat the same operation using a language (i.e. Spanish) that has special characters. Check that these are displayed correctly and that there are no char sequences such us "Å~"