ci session via proxy

[eluser]ReGeDa[/eluser]
Hi, friends!
I hava some problem with session via proxy. I used $this->session->unset_userdata(...) on logout my user. But! I get a page with data of lost user (no session data) - data on page (such "my photos", "my mail"). It will be hidden. My opinion - proxy cached this page. I'll take an advice.
Sorry for my English! I'm from Russia. Student