Basic MSI Conditions: 1) Use cyrillic language as 2nd interface language (for example Russian) 2) Set language for non-Unicode programs as English (Control Panel\Regional and Languages Options\Advanced) 3) Run setup from generated distributive and choose "Russian"
If you are using the ANSI setup.exe (Releases view, select your release, go to the Setup.exe tab, check Setup launcher type) then this would be expected behavior. Cyrillic characters can't typically be converted/represented on the English codepage, which is why the characters show up as question marks. A Unicode version of setup.exe has been provided since IS 2009 (change the Setup Launcher Type release setting to Unicode) that should resolve this behavior.
