Suddenly I discovered that from 11 days a process is eating all the power. Top says:
14 0 856 788 584 R 0 98.2 0.6 17047m /usr/X11R6/lib/X11/fvwm95//FvwmTaskBar 9 4 /usr/X11R6/lib/X11/fvwm95/.fvwm95/post.hook 0 8 The process belongs to the user (not shown above) that is not logged in for at least some days. This time I will simply kill the process, but how to avoid such situations in the future? Blazej