Sorry for late response.
Step by step:
1) I start rTorrent, settings from .rtorrent.rc are loaded.
2) I open ruTorrent frontend, default ruTorrent settings are applied to rTorrent.
3) I set up what i need to on ruTorrent configuration screen, press ok; rTorrent now has these new settings.
4) I reload (or close/open) ruTorrent page, default ruTorrent settings are applied again to rTorrent (as if configuration on step 3 never took place).
Thanks in advance for your support.