Hello, I searched on this support forum and it is a little mess, so I decided to write down simple user quide how to make transaltion works.
1. Download translation on: http://plugins.trac.wordpress.org/browser/wp-polls/i18n/
2. Upload BOTH files (*.mo, *.po) to root of the WP-Polls directory.
3. IMPORTANT: go to in administration: Polls -> Templates menu and RESET them all to defaults, Save changes and wait...It worked on my site.
If the frontend is not translated try it once or twice more a watch how the codes in the templates settings are changinng to your language.
I did it twice and it was ok in backend and frontend.
I am NOT a programmer, so don`t ask me for a code questions, thx :D