LENOVO ThinkPad L512 (2597AB2) Fan speed freezes, and hotkeys stop working ubuntu 12.04.2 and 12.10

Lenovo L512 (2597AB2) ubuntu 12.04.2 and 12.10

I've purchased LENOVO ThinkPad L512 (2597AB2) laptop, and experiencing some problems with it in Linux. Particularly, after some time (it may be 10 minutes, or may be day) buttons Fn + F1, Fn + F2, ..., Fn + F12, Insert, Delete, Home, Volume+, Volume-, Volume Mute are no longer works. Also CPU fan behaves strangely: it stops, then it goes to it's max RPM, than it stops again, etc. And it does so until one completely cuts laptop from the power (no AC, no battery), reboot or on/off cycle are unhelpful.