should I open a bug on it?
RR isn't an ubuntu package, issues should be posted here

http://code.google.com/p/rubyripper/issues/list

Did you build or install from a package?

RR can be built with multiple locales (translations), whether that would have any effect on your issue don't really know, though I see a ru folder in the build I did. ( have no idea what it's for..?

/usr/share/locale/ru/LC_MESSAGES/rubyripper.mo