I forgot to write that I have had installed overclock profile (700 MHz) when failure took place.
ls -al /mnt/maemo/lib/modules ls -al /mnt/maemo/usr/share/kernel-power-settings
Nokia-N900:~# ls -al /lib/modules/ drwxr-xr-x 4 root root 376 Jun 18 2015 . drwxr-xr-x 10 root root 7840 Jun 16 2015 .. drwxr-xr-x 2 root root 984 Oct 14 16:54 2.6.28-omap1 drwxr-xr-x 2 root root 23744 Oct 14 16:54 2.6.28.10-power53 lrwxrwxrwx 1 root root 17 Jun 18 2015 current -> 2.6.28.10-power53 Nokia-N900:~# ls -al /usr/share/kernel-power-settings/ drwxr-xr-x 2 root root 616 Jun 15 2015 . drwxr-xr-x 123 root root 9960 Jan 6 10:01 .. -rw-rw-r-- 1 root root 499 Nov 1 2011 default -rw-rw-r-- 1 root root 499 Nov 1 2011 dsp -rw-rw-r-- 1 root root 470 Nov 1 2011 ideal -rw-rw-r-- 1 root root 499 Nov 1 2011 lv -rw-rw-r-- 1 root root 476 Nov 1 2011 starving -rw-rw-r-- 1 root root 499 Nov 1 2011 ulv -rw-rw-r-- 1 root root 499 Nov 1 2011 xlv